The main range of the Spencer Mountains is formed by contorted sandstones and slates, which to the west are followed by a narrow band of micaceous schists. Beyond these granite forms a range called the Victoria Mountains, which is parallel to the Spencer Mountains. East of the Spencer Mountains, much-jointed sandstones and mudstones form the lower ranges surrounding the Hanmer Plains, the only known eruptive rock being a small syenite boss at Hurunui Peak and the Mandamus River. These sedimentary rocks are of carboniferous and triassic age, some, perhaps, being jurassic. Bordering them on the north side of the Hurunui Plains, and stretching north-west towards Kaikoura, tertiary limestones, sandstones, and clays are found, which are of oligocene and miocene age, and among them volcanic rocks, not younger than miocene, occur in three places—(1) Where the River Pahau enters the Hurunui Plain; (2) at Lyndon, about nine or ten miles due east of Hanmer Hot Springs; and (3) up the Mason River, on the Highfield Station, about five miles east of the last.

The Hanmer Hot Springs occur on a clay terrace on the north side of the plain, and are at a height of about 1,200ft. above the sea. There are ten springs, two of which are cold, the rest warm; the hottest having a temperature of about 117° F. In cutting a ditch for laying pipes to take away the overflow from the baths, a layer of black peat, some 6in. or 7in. thick, with tough clay on each side, was found. This layer would pass about 10ft. or 11ft. under the bathhouse, and probably some 15ft. below Spring No. 1. One of the springs (No. 9) often brings up small fragments of this peat; so that it probably spreads under the whole. Complete analyses have been made of the water from three of the hot springs by Professor Bickerton. They are all alkaline. The salts in the springs are chiefly sodium-chloride, but in addition there are alkaline sulphates and carbonates in about equal quantities. The ammonia and albuminoid ammonia are no doubt derived from the layer of peaty matter which the waters pass through; and, no doubt also, this organic matter reduces part of the alkaline sulphates to the condition of sulphides, which are decomposed by the action of carbonic acid derived from the peat, and changed into alkaline carbonates with the disengagement of sulphuretted hydrogen: some of the latter may, however, be derived from the albuminoid ammonia. The passage of the water through the peat-bed is too rapid to allow of the whole of the sulphates being changed into carbonates; but in all probability no carbonates and no sulphuretted hydrogen, and certainly no ammonia, exist in these waters below the peat-bed. The heat of the water makes these reactions go on energetically, but the reactions

do not themselves give rise to sufficient heat to heat the water. The water must be hot before it reaches the peat-bed.^*

I mention these details because it has been supposed that the presence of sulphuretted hydrogen in these springs indicates the presence of volcanic energy below the Hanmer Plains, which has been supposed to be connected with the origin of the earthquake.

Other hot springs occur in Cow Creek, a branch of the Edwards River;^† in Cannibal Gorge; in the Upper Hope; in

Woodbank.—Partly brick and partly wood. The brick portion, which was very old, had two walls thrown down. The wooden building was not much damaged, but shifted bodily 2½in. to the east. The chimney fell to the west. A concrete chimney between the two parts of the house was broken off at the roof, and the upper portion was thrown upwards and fell to the east. A cob hut has the south-west corner knocked out; the west end would have fallen, but was held up.

Hot Springs.—No damage was done; but the only chimney is low, and of concrete.

Jack's Pass Hotel.—No damage done, and very little breakage of glass.

St. James'.—Chimney-tops fell on earthquake of the 28th September; but it is thought that they were cracked through by the shock of the 1st September, but did not then fall.

Jollie's Pass Hotel.—-No damage done, and very little breakage of glass.

St. Helen's.—The three chimneys were thrown down. They fell in different directions. Hams were thrown off hooks, as also was a birdcage.

Ferry Hotel, Upper Waiau-ua.—This is an old cob building, but it was not much damaged.

Tekoa.—A brick house. The upper portions of the walls fell, it is thought because they were not so well built as the lower portions.

Balmoral.—No damage reported.

Culverden.—At the station three or four chimney-pots fell. At the township no damage is reported.

Montrose.—The tops of two chimneys fell.

Leslie Hills.—A stone building. The walls were cracked in various directions, and the five chimneys fell, the north-west portion being the most damaged. The old building with cob walls, in very good condition, stood better than the stone. The men's hut, ten chains from the house, and built of cob, received no damage—even an old chimney, partly cob and partly brick, was not injured.

Lyndon.—A chimney was thrown down.

Waiau Township.—Several chimneys were thrown down, and a granite monument in the cemetery was overturned. It was a pyramid standing on a granite base. The pyramid only was overthrown.

Highfield.—Three chimneys fell. An outside one was completely wrecked; the two inside ones were broken off at the roof. They fell in three different directions.

Kaikoura.—One or two chimneys were thrown down, and others were cracked.

have been filled up again before November. Small landslips occurred in the cutting leading to the bridge over the Waiauua, and two larger ones at the approach to the ferry. Up the Waiau-ua no fissures are reported until opposite the Grantham River, where there are some cracks 4in. or 6in. wide. From here, along the south side of the river, they get more and more abundant to Hopefield and Glynn Wye, but were seldom more than a foot in breadth, the larger ones being generally near the river. On the flat of Shingle Creek there were several fissures 4in. to 6in. wide. A large fissure was reported at the back of the house at Hopefield, and two circular holes about 4ft. in diameter and several feet deep are said to have been formed near Glynn Wye. Near this place fissures were very numerous in the terraces, some being more than a foot wide. Up the Hope they were still larger, some being more than 2ft. broad and several feet deep. Wire fences on the terraces were moved in places from 5ft. to 8½ft. horizontally. All these fissures were in alluvial deposits, and were more or less parallel to the valley of the Hope and Waiau-ua Rivers. Above the junction of the Boyle with the Hope the fissures get smaller and less numerous and more confined to the edge of the terraces, but there are numerous landslips on the sides of the mountains. Beyond Kiwi Creek no fissures have been noticed in the valley of the Hope, but some continue up the alluvium of Kiwi Creek. None are reported in the valley of the Boyle, and none in the Waiau-ua above Hopefield. As a glance at the map will show, all these fissures are confined to the alluvial deposits; none have been detected in solid rock.

At Tekoa Station, on the Mandamus River, numerous and large blocks of rock fell from the cliffs, making a great noise.

In the Bealey several landslips occurred, and in the Otira Gorge part of the road slipped down. At the accommodation-house at the entrance to the Otira Gorge the shock was felt very severely. Stones and rocks rolled down the mountainside in great numbers, striking each other and leaving long trains of fire behind them—a phenomenon which has been observed before in landslips. A large fissure was formed in Kelly's Creek, but I have not been able to obtain any particulars about it.

A miner from the Totara Flat District, between Greymouth and Reefton, reports that a number of trees on both sides of his claim were thrown down; and this was probably due to slips. A shepherd who was in Jones's hut, in the Upper Hope, also reported that dead branches were shaken from the trees, and it appears that many dead trees were also broken off about 10ft. from the ground, some at least a foot in diameter. In some places near here green trees 25ft. to 30ft. in height have been torn up by the roots; and this was probably due to slips.

observations on the intensity of the shock cannot do more than give us a rough approximation to the position of the epicentrum; nevertheless, this approximation, although rough, will be undoubtedly correct so far as it goes, and will thus enable us to discard evidently erroneous observations of the second and third class of evidence. I shall therefore begin with the evidence of the first class.

Intensity of the Shock at Different Places.—The intensity of shock can be roughly estimated by the damage done to buildings, or to glass and crockery on shelves; but great anomalies occur locally (which will be considered later on), and it is only by taking a comprehensive view that we can arrive at any results. There is no difficulty in concluding that where wooden houses have been wrenched out of shape the shock has been more intense than where chimneys only have suffered. But there are great differences in chimneys—in proportions, in supports, in construction, and in materials—and we cannot make any close comparison between them. Bottles and crockery on shelves are, however, under more similar conditions, and afford a better comparison than chimneys in estimating the relative intensity of the shock. Fissures and landslips also afford good evidence when the conditions are tolerably equal.

From the record of facts already given it will be seen that Glynn Wye, on the River Hope, appears to have sustained the greatest shock. It is the only place where wooden houses have been wrenched out of shape; and here the fissures and landslips are greater than elsewhere.

Glass and crockery were thrown off shelves at Waikari, Rangiora, Reefton, Westport, Greymouth, Marsden, Notown, Kumara, and Hokitika, all being within a radius of seventy miles from Glynn Wye.

Chimneys were thrown down or damaged at Kaikoura and Christchurch, within a radius of eighty miles of Glynn Wye; and slight damages are reported from Ashburton and Nelson, each about a hundred miles from Glynn Wye.

At further distances no damage was done to buildings. The greatest damage, however, does not take place at the epicentrum, where the shock is vertical, but where the direction of the wave makes an angle of between 55° and 45° with the horizon; consequently the position of the epicentrum would probably be somewhere to the west of the meridian of Glynn Wye; and Mr. O. Thompson, the manager, says that the shock passed to the eastward, down the valley, with a hoarse crashing sound which gradually died away in the distance, while things were quiet at the place where he stood. At Reefton no chimneys were thrown, so that the shock there must have been less than at the Hanmer Plains. This may have

been due in part to the intervening ranges of mountains, but it prevents us locating the epicentrum very far west of Glynn Wye.

If we assume that the meizoseimic band extended three miles on either side of Glynn Wye, and that the angle of emergence was 55° on the western edge of this belt and 45° on the eastern edge, it would indicate that the epicentrum was about seventeen miles from Glynn Wye, and about twenty miles below the surface.

Mr. A. McKay, in his report, says that he is of opinion that the shock “commenced at some point to the west of Glynn Wye, perhaps further west than the junction of the Kiwi with the Hope, and that it travelled eastward with increasing force to Glynn Wye and Hopefield, beyond which places, by what appears at the surface, its destructive character began to be less.” The junction of the Hope and the Kiwi is fourteen miles west of Glynn Wye.

Direction of the Shock at Different Places.—Reports under this head vary extremely, even from the same place, and in the absence of seismographs no accurate results can be expected. It is known from observation that the normal wave is followed by a transverse wave, and that afterwards the ground oscillates irregularly; so that, even if the direction be estimated right, it would be impossible to distinguish the normal from the transverse wave. Even accurate observations may often give a wrong direction. For example: The movement of cream in a pan at Rangiora gave S.W. and N.E. as the direction. At Ohoka the same kind of seismometer registered the shock as E.S.E. and W.N.W. At Ashburton a lamp was seen to swing east and west. In Christchurch water was thrown out of buckets in different directions in the same building, although in the majority of cases it was to the N.W. In fact things in general seem to have been thrown away from a wall without much reference to the shock. In the Canterbury Museum some unsupported table-legs in the Indian case fell to the east; but I found that the shelf on which they stood had a slight slope in this direction. All these and many others must be rejected as pointing far out of the direction of the normal wave; and, indeed, but little weight can be attached to this kind of evidence at all: but, as it is quite independent of all other evidence, it may be worth while to find out what results it leads to.

At Wellington the seismograph is reported in the newspapers as registering the shock N.E. and S.W.; at Christchurch the cathedral-spire is octagonal, and the cross fell over to the side facing N.W. This no doubt shows roughly the true direction of the shock, but it might have come from any point between W.N.W. and N.N.W. I will take it at N.W.

The other places from which I have records pointing more or less in the true direction are—Greymouth, E. and W.; Notown, S.E. to N.W.; Westport, S.E. to N.W.; Reefton, S.E. to N.W.; Boatman's, first shock E. and W., second S.E. to N.W.; Lyell, S. to N., or S.E. to N.W.; Nelson, S.W. to N.E.; Blenheim, S.W. to N.E.; Kaikoura, N.N.W. to S.S.E.; Waikari, N. and S.; Leeston, N. and S.; and Kirwee, N. and S.; or fourteen stations in all. I have also ten other stations, in which the directions given are too wide of the mark to be of any use. They are—Rangiora, S.W. to N.E.; Ohoka, E.S.E. to W.N.W.; Ashburton, E. and W.; Lauriston, S.E. to N.W.; Glentunnel, E. and W.; Timaru, between W. and N.; Queenstown, N.W. to S.E.; Dunedin, E. to W.; Invercargill, W. to E.; Manaia, S. to N. (nearly correct).

If we project the fourteen fairly accurate directions on a map, and then describe the smallest circle possible which will touch or cut all the lines, it comes out that the circle has a radius of about thirty miles, and its centre is situated at the Amuri Pass, at the head of the Doubtful and Ahaura Rivers, about seventeen and a half miles W.N.W. of Glynn Wye. This approximation is nearer the truth than could have been expected.

Time of the Shock at Different Places.—Time-observations are subject to error from the clock not showing correct time, from incorrect readings, and from observations being taken at different periods of the shock. The first source of error is got over by comparing the clock with telegraph-time as soon as possible after the shock. When a clock is stopped by the earthquake the second source of error is eliminated; but the first and third remain. If, however, the time of the shock is correctly given to the nearest minute, and the stations, are sufficiently distant from each other, fairly accurate determinations may be made from them; and experience has shown that in a civilised country, with telegraphs and railways, these time-observations are of great value. The following are the times reported:—

A cursory inspection of this list will show that many of

The time the shock took place at the centrum will be between 4h. 4·85m. and 4h. 4·19m., or, say, 4h. 4m. 30s.

But at stations like Ashburton and Christchurch, which are at a considerable distance from the epicentrum, the depth of the centrum will affect the distance very little, and therefore the velocity of propagation calculated from these places will be almost independent of z. Assuming that the time of shock at the centrum was 10h. 4·5m., and that the depth of the centrum was 20 miles, the distance of Christchurch from the centrum will be about 79 miles, and that of Ashburton about 104 miles. The time of shock at Christ-church was 4h. 12m., and at Ashburton 4h. 13·5m.; consequently the velocity of propagation to Christchurch was 10·5 miles per minute, and to Ashburton 11·5 miles per minute, the mean being 11 miles per minute, or 968ft. per second. This indicates the depth of the centrum at 24 miles, and probably about 20 miles is as near an approximation as the nature of the data at our disposal will admit of. The size of the centrum we have no means of estimating.

From this it follows that the wave arrived at the epicentrum at about 4h. 6m., and that the average velocity of propagation along the surface was, from the epicentrum to Boatman's, 1,584ft. per second, and from Boatman's to Westport 1,232ft. per second.

In attempting to locate the epicentrum from time-observations it is assumed that the rate of propagation was the same in different directions; and the result of that attempt agrees so closely with the result arrived at by the methods of greatest intensity and of direction of shock that we may conclude that, to the places used for this purpose, the rate of propagation was approximately the same, and that it was about 12·3 miles per minute, or 1,082ft. per second, along the surface.

If, however, we take the distant stations, we find a much faster rate: to Timaru, 28·4 miles per minute; to Dunedin, 27·4; to Invercargill, 36·1; and to New Plymouth, 29·7 miles per minute. As it is impossible to suppose that the earthquake travelled faster at a distance than it did near its origin, it looks at first as if there must be errors in the time. But if we assume that it travelled at the rate of 12 miles per minute all round, it should have arrived at Timaru at 4h. 18m.; at Dunedin at 4h. 26m.; at Invercargill at 4h. 33m.; and at New Plymouth at 4h. 28m. This supposes errors in time of from seven to eighteen minutes, which could not have been the case. The only possible explanation that occurs to me is that the shock was transmitted with great velocity along the mountains in a south-west direction to Queenstown, and that Invercargill and Dunedin received the shock from there. This would agree with the direction of the shock given at Dunedin,

the shock of 2.30 a.m., 12th October, was followed by incessant booming like the fire of artillery in the distance, but some of the explosions seemed quite close at hand. A visitor thus describes them: “On Friday, the 12th October, at 2.25 a.m., I was awakened out of sleep by a most violent shock, or, rather, double shock, as there was a break of some two or three seconds in it. As soon as this had subsided these underground explosions began, and followed each other at intervals of, say, five seconds for some minutes, when they diminished in quantity but increased in strength, until every explosion made the house (a galvanized-iron one) quiver and rattle. This continued until 8 o'clock a.m., during which time we had seventeen shocks, five of which may be termed sharp.” I myself heard two booms on the 3rd November and three on the 9th November. Those of the 3rd November were at about twenty seconds' interval, and each lasted about five seconds. The sound was like that of a distant avalanche; they were not loud, and were not followed by any shock. Those on the 9th November were of quite a different character: they were short and sharp, like the explosion of a cannon at a distance. They were not followed by a shock, but I fancied that there was a slight shake simultaneous with the sound and quite as short. This, of course, would be an air-reverberation, and not an earth-wave. One of these booms was at 10.30 a.m., another at 3.14 p.m., and the third at 3.20 p.m. There was also another of a similar nature at about 2 a.m. the next morning. Mr. McKay mentions having heard noises of two different characters—one on the 7th October, which resembled the rumble of a distant avalanche, and was accompanied by a slight shock; the other, which was later on the same day, resembled a strong blasting-shot in a mine, and was not succeeded by a shock. Inquiries made on the ground lead me to think that these two kinds of sounds have been heard all through, and that each kind, when loud, was followed by a slight shock at about two seconds' interval.

On the 13th November there was a loud boom at 2.10 a.m. and another at 10.5 a.m. Both these were followed, at between one and two seconds' interval, by a sharp short shake, like the blow of a hammer, quite distinct in character from the earthquakes unaccompanied by a boom, one of which took place at 11 a.m. on the same day, and has already been mentioned as a swaying movement lasting for thirty seconds.

These sounds have been heard in the valleys of the Hope and the Edwards, and doubtfully at Cannibal Gorge, as well as on Hanmer Plains and the hills immediately surrounding them; but they were not heard at Culverden or Waikari on the south, nor at Tarndale on the north, nor at Reefton or Boatman's or Lyell on the west. At the Hanmer Plains it is

generally agreed that they came from various directions between west and north; and they appear to me to proceed from an elongated area some thirty miles in length, between the hot springs in the Hope and the hot springs in Cow Creek, or perhaps from the neighbourhood of these two localities only.

As a rule the hot springs at Hanmer showed no sympathetic action with the noises, the only exception being a sharp boom, like a cannon-shot, at about 11.15 a.m. on the 14th September, accompanied by a shock which appeared to be nearly vertical. On this occasion a small quantity of mud and water was thrown from one of the smaller springs only.

It is difficult to offer a satisfactory explanation of these noises: they have been heard with other earthquakes, but never explained. In our case it is evident that the main earthquake, and all those of the same character that followed it, were quite independent of the cause of the booms. This is shown by the fact that many shocks were not accompanied by any noises, although they were heavier than those following the booms, and also by the heavier shocks of the 1st September, 28th September, and 12th October being followed, not preceded, by noises for several days. On the other hand, as the booms were heard before the main earthquake, their origin must be independent of it; but, as they were far more frequent and much louder after the shocks, it is evident that to a large extent they were secondary effects of the earthquake.

Mr. Mallet suggests that the noises heard after the Cachar earthquakes of 1869 were due to grinding or crushing of rocks; but this explanation will hardly do for our case, because many of the earthquakes were not accompanied by noises, and the booms do not come from the direction of the epicentrum of the earthquakes. The sounds appear to me to be much more like explosions of steam than crushing of rock; and this seems to be the only other explanation. There is no direct evidence to show that they are connected in any way with the hot springs, but their geographical distribution strongly suggests it. Hot underground water undoubtedly exists in the district in which the sounds have been heard, and at a comparatively small depth this water may be above the boiling-point, but kept fluid by pressure. If this pressure were removed, part or the whole might flash into steam and produce an explosion which would cause a boom. An earthquake might first compress this water, and then, on the backward swing of the wave, the pressure would be relieved and explosions take place; or part of the heated water might be expelled by the shock, which would reduce the pressure on the rest. It seems useless to offer such speculations as these, and I should not have done so if it had not been suggested that these explosions

to apply it to our earthquake it will be useful to explain the theory rather more fully.

Rock, of all kinds, is a more highly elastic material than alluvial gravel or sand, and when an earth-wave passes from rock into alluvium it will, unless it be perpendicular to the plane of junction of the two formations, be partly reflected downward and partly refracted towards the perpendicular to the plane of junction (Pl. XVII., fig. 1). If, however, the direction of the wave was very oblique to the plane of junction, the whole wave might be reflected down into the earth, and no shock would be felt on the alluvium (Pl. XVII., fig. 2). On the other hand, when the wave passes from alluvium into rock the refracted portion will be bent away from the perpendicular to the plane of junction, and the reflected portion will have its angle of emergence increased (Pl. XVII., fig. 3); but if the angle is small between the direction of the wave and the plane of junction, then total reflection of the wave in an upward direction will take place (Pl. XVII., fig. 4). This upward reflection might be in the same azimuth as the direction of the earth-wave, but more commonly the wave will be diverted to the right or left according to the inclination of the plane of junction. It is only the cases of total reflection that need be considered here.

The slopes of old valleys covered up with alluvium vary very much; but, as the earth-wave is always more or less emergent, the angle formed by the wave with the plane of junction on entering alluvium will generally be greater than the same angle when the wave is leaving alluvium: consequently, total reflection will be rare where the wave enters an alluvial plain, but will be common where the wave leaves it. A glance at Plate XVII. will explain this. It follows, therefore, that along those margins of alluvial plains where the rocky slopes face the origin of the earthquake the shock may be doubled or trebled in force; while along those margins where the rocky slopes are turned away from the origin the shock will either be normal or will be diminished in intensity. This does not apply to a narrow valley, for in that case the whole contents of the valley would be forced to vibrate as one system with its rocky walls, and there would be neither refraction nor reflection. I will now try to apply these principles.

Jack's Pass Hotel (31 miles from the epicentrum), Jollie's Pass Hotel (34 miles), and Culverden Station (34 miles) are in narrow valleys, and would receive the normal shock only.

Balmoral (30 miles) and Montrose (32 miles) are on alluvial plains near the margin where the wave entered alluvium from rock, and consequently the shock in these places was probably normal also.

Ferry Hotel, Waiau-ua (29 miles distant from epicentrum), is built on rock which is cut off from the earthquake-origin by an alluvial valley; it would therefore, in all probability, receive less than the normal shock due to its distance, because some of the waves may have been totally reflected upwards before reaching it. This hotel is an old cob structure, and manifestly it has not undergone such a severe shaking as Woodbank or St. Helen's were subjected to.

Leslie Hills (33½ miles distant from epicentrum) undoubtedly received a more severe shock than did Montrose or Balmoral, and it is situated on the margin of an alluvial plain, where the wave passed onwards into rock, and consequently in a position where we might expect an increase in the violence of the shock from total reflection upwards. The same explanation applies to Highfield (46 miles distant), where several chimneys were thrown down; for it stands on an alluvial terrace, with hills behind which face westerly.

St. Helen's certainly received a more severe shock than its distance from the epicentrum (32 miles) would warrant, although it stands nearly in the middle of the eastern half of the Hanmer Plains. But the evidence shows that the wave emerged here at a high angle. Hams and bacon were thrown off hooks; a birdcage was also thrown off a hook, and ice was thrown up out of a pool. Evidently the angle of emergence was greater than usual, and I should account for this, as well as for the increased intensity of the shock, by the supposition that the spur between the Hanmer and the Percival Rivers runs down under the alluvial plain below St. Helen's and acted as an earthquake-reflector upwards. It has been supposed that the ground on which. St. Helen's is built is swampy, and that that would account for the damage done to the house; but it would not account for the increase in the angle of emergence, and, after seeing the locality, I feel inclined to reject the swamp theory altogether.

At Woodbank (28 miles distant) the shock was undoubtedly more severe than its mere distance from the epicentrum would explain. I do not take into consideration the brick portion of the building, which was old and put up with bad mortar, but the wooden part of the house, which was shifted bodily 2½in. Here, also, cob huts, not worse built than the Ferry Hotel, were rendered quite uninhabitable, while the Ferry Hotel, only one mile further from the epicentrum than Woodbank, was scarcely injured. At Woodbank, also, a cement chimney-top was thrown up and then fell over on to the roof of the wooden part of the house, which indicates not only a very strong shock, but also a high angle of emergence. This is confirmed by Mr. Atkinson, who says that when standing outside his house immediately after the first shock

of them are small and local, but others are far more violent than earthquakes due to explosions of steam, and, as the centrum is often deeply seated, they are often felt over a very wide area.

The earthquake of Wellington in 1855 was one of this kind, as also are, no doubt, most or all of those in the South Island. The Wellington earthquake, however, belongs to a very rare class, in which the centrum extends to the surface, and surface-rocks are moved. In a large majority of cases no movement takes place in the surface-rocks^* except that due to the earth-wave generated below by the fractures.

Small earthquakes may not be accompanied by actual fracture of rocks; and when there is no fracture no noise will be heard, although the shock may be felt for a considerable distance: for the waves of sound in the earth are produced by the fractures.

In the earthquake we are now considering the shake was of an unusual character, inasmuch as it was long and even, without any violent jerks; but, as it was accompanied by a sound-wave, fractures of some kind must have taken place. These fractures could not have been due to an explosion or to a very sudden break or split: they appear to me to have been due to a slow splitting or crushing of rocks.

At first sight the evidence seems to favour the idea of a slow splitting having taken place along an east-and-west line in the valleys of the Waiau-ua and Hanmer, for it was in this direction that most of the damage was done. But this idea is much weakened when we remember that this is the only line which is even fairly well inhabited, and is the only line along which an alluvial valley approaches the epicentrum; and when we examine the evidence attentively I think we must give up the idea altogether. It is certainly in favour of it that a better explanation could then be given of the destruction caused at Woodbank; but this is the only favourable fact that I can find, for no fault or fissure has been proved from other evidence to exist in the valleys of the Waiau-ua and Hanmer, and no fracture or movement of solid rock has been found anywhere in the neighbourhood. On the other hand this line has a distinct meizoseimal band, and if it were a line of fissure reaching to the surface the shock would have commenced at this band and gone both ways, which is distinctly contradicted by both an eye-witness and by time-observations. Again, the Ferry Hotel stands on the very edge of this supposed fissure, and ought to have suffered more than Leslie Hills or Highfield. And, again, no explanation is in this way given of the strength of the shock at Tekoa and in the Otira,

in Wellington, in 1882, and since that time I have used it for various purposes. Under the microscope I found diatoms in it, but was then very ignorant of the whole subject, and was unaware that any new forms existed in it; but from remarks passed by Mr. McKay I gathered that the earth, or ooze, had more than passing interest, and thus I was induced to give some of it to Mr. Robinson for the Exhibition. Shortly after Mr. Robinson informed me that he had received a report on the earth from the Geological Department that it was not kaolin, but “diatomaceous earth.”

Messrs. Grove and Sturt are amongst the foremost of the authorities on Diatomaceæ in Great Britain. The former some years ago investigated and described some of our New Zealand freshwater Diatomaceæ sent to him by the late Mr. Inglis, of Christchurch.^* These gentlemen at once recognised the richness of this deposit, and ascertained the presence of a number of forms new to science. In their papers and reports referred to above they give a description and list of 283 forms, of which 107 are new species or varieties. They also have discovered four new genera—Anthodiscus, Kittonia, Monopsia, and Huttonia, the latter named after Captain Hutton—and a new sub-genus, Pseudo-rutilaria. Since then other samples of diatomaceous ooze from other localities—which, as I will presently show, vary considerably from that at Cormack's siding—have been sent to these gentlemen; and I have no doubt but that the list of species will be much extended.

In their first communication Messrs. Grove and Sturt note that the deposit consists “mainly of diatomaceous remains, with a small proportion of Radiolaria and sponge-spicules:” and they call attention to the interesting and curious fact that several of the forms existing here have previously only been found in the Cambridge Estate, Barbadoes; that others, again, resembled forms found previously only in Simbirsk, in Russia, and also at Brünn, in the fossil condition; and they remark that several of the forms are still to be found living in the Indian Ocean.

Since I commenced this paper I have received from Mr. Grove a very valuable and representative collection of Diatomaceæ from various parts of the world, in which he has taken the trouble to select and mark diatoms found in Japan, Hongkong, Fiji, and Bombay, in the living conditions, exactly similar to those found here in Oamaru as fossils. A slide from the Barbadoes deposit is very similar to one prepared from our deposit; and I have found similar diatoms in ooze gathered in the “Challenger” expedition given me by

Dr. Colquhoun, and also in some diatoms found in guano given me by Dr. de Zouche.

This discovery led to much inquiry, and many were the requests sent to various persons in Oamaru from all parts for specimens of the earth; and I am sorry to say that a great deal of the wrong material has been sent away—perfectly useless. One parcel alone of nearly 2001b. weight contained only one or two lumps of earth containing diatoms, and those were by no means rich.

To obviate this, and avoid disappointment for the future, I have prepared a map of the district (Pl. XVIII.) showing the deposits as far as they have been hitherto found, and the roads leading to them. The deposits are so extensive that there is no fear of their becoming exhausted. One alone at Jackson's is about a quarter of a mile long, and shows a face of some 60ft. How far it goes back I have no means of ascertaining. I have also prepared diagrammatic sketches showing the appearance of the deposits as exposed, and the relation of the diatomaceous ooze to the other earths.

Plate XIX., fig. 1, shows a section of the railway-cutting at Cormack's siding. Here the prominent feature is the volcanic dyke, b, cutting through it; on each side is a hard white earth very similar to the proper diatom ooze in appearance, but heavier and much harder. This is the earth which has been sent home, and which has led to so much vexation. It is more easily collected. Between the volcanic dyke and this hard material there is a distinct line of demarcation, but none exists between the hard material and the true diatom earth; and as a matter of fact the further away from the dyke the richer is the ooze in diatoms and other siliceous remains. Hence I would infer that the intruding dyke has heated and partly fused and compressed the diatom earth through which it has burst. The same condition is found in various other places where dykes exist or where there appears to be a flow of lava, as under Jackson's paddock (Plate XIX., fig. 2b): there, along the road-line, is a volcanic layer similar in its appearance to the dyke at Cormack's, and with the same hard white stuff. At many points in Cave Valley, and in the Waiarekei Valley below Jackson's, Bain's, and Totara, does the same condition exist; and also, in the neighbourhood of these places the plough turns up pure diatom ooze. The diatom ooze, also, at Cormack's, as in the other sub-volcanic deposits, is non-calcareous. Microscopically it is peculiar in the number of a species of diatom called Stephanopyxis present in it, and which may be said to be characteristic of it. Also, this non-calcareous ooze has a much smaller quantity of Radiolaria—i.e., Polycystinæ, &c.—and sponge-spicules in it than the calcareous diatom ooze which is found above the volcanic remains. I have

endeavoured to show this in Plate XX., fig. 1, representative of Cormack's siding; fig. 2, of H. Allen's. (The sub-volcanic deposit at Bain's is very similar to these.) In these it will be noticed that the diatoms, Polycystinæ, and sponge-spicules are much smaller than in figs. 4 and 5, which represent the forms found in the supra-volcanic calcareous diatom earth in Jackson's and Bain's; also that in the former or sub-volcanic deposits Stephanopyxis abounds, and is absent, or, at any rate, rare, in the latter. Fig. 3 shows a peculiar deposit on the Totara Estate. It is a continuation of the upper layer of Bain's sub-volcanic layers, and lies somewhat higher. I am unable to account for the minute character of the diatomaceous remains found here unless it be a question of gravity, and that the diatom mud was shaken up and the heavier forms fell to the lower depths.

Although the large forms are much more abundant in Jackson's and Bain's, and much more perfect, it must not be assumed that they are absent in the other deposits, for they are found, but only in fragments and scarce. Mr. Grove accounts for their better preservation in Jackson's by the larger forms of the sponge-remains and the great quantity of the spongioliths: the diatom-valves falling amongst them would be protected.

I suggested previously that the hard white material was altered and semi-fused diatom earth—altered by the action of the intense heat of the volcanic lava in the dyke. This theory seems confirmed by the conditions of the layers at Bain's and at Allen's. Here the volcanic remains consist of tuff, or volcanic ash, and this seems to me to have settled down on the diatomaceous ooze in a cooled state, for I find that the white earth immediately attached to the tuff is just as rich in diatoms as any other part of the deposit; and, indeed, some of the tuff is perforated by or surrounds hollows filled up by pure diatom ooze.

I have not yet referred to the Ototara limestone lying above the diatom earth and the volcanic remains, and feel very diffident in putting forth any theory on the geological conditions and ages of the deposits, but I will do so in order to invite discussion and obtain information from those well calculated to give it.

It seems to me that at a very early period of the history of this part of the world matters were very quiet, and that there was a greater excess of vegetable life, and that animal life was then less abundant. This period of rest was disturbed by volcanic irruptions, and possibly the levels were altered. After this disturbed era had passed away a fresh growth of vegetable and animal life followed, but, owing to some change of conditions, the animal life, as represented by the Polycystinæ and sponges,

became more abundant and prolific; then, in order to fulfil their functions in the balance of nature, the Diatomaceæ also increased in number and size; and, finally, that, the conditions being prepared for them, the higher forms of animal life appeared and formed the limestone.

Dr. G. Hartwig in “The Sea and its Living Wonders” says, “Without the diatoms there would be neither food for aquatic animals nor (if it were possible for these to maintain themselves by preying on one another) could the ocean waters be purified of the carbonic acid which animal respiration would be continually imparting to it. Thus it is not in vain that they abound in the most inhospitable seas, where but for them no sea-bird would flap its wings, and no dolphin dart through the desert waters.”

Dr. Hartwig also states that they increase so quickly and multiply by division (other authors say also by conjugation) that in forty-eight hours a single diatom may multiply to 8,000,000, and in four days to 140,000,000,000,000, “when the siliceous coverings of its enormous progeny will already suffice to fill up a space of two cubic feet.”(!)

Many other remains found in these earths are highly interesting, and no doubt are new to science. The Foraminifera are very abundant, especially in the calcareous deposits. I have figured a few, Plate XX., fig. 6. The Radiolaria and Polycystinæ are very striking and beautiful forms. As for the spongioliths, they are so abundant and fine in Jackson's deposit that Mr. B. W. Priest, an authority on the sponges, states that for “size, variety, and quantity this deposit far surpasses any previously discovered.” Dr. Hind, I may add, is preparing a monograph on the spongioliths of this locality.

In examining the various deposits, and in working out various details in connection with this paper, I have received much assistance from Messrs. John Forrester and C. Peach, of the Oamaru Harbour Board. Mr. Charles Gifford, of the Waitaki High School, was, I believe, the first to find out and examine the deposit in Jackson's paddock. Mr. Th. Isdaile, of Enfield, has also given me much valuable information.

With regard to the practical uses to which diatomaceous earth may be applied, much, I imagine, depends upon its purity and the relative quantity of silica which it contains. I regret that I have been unable to get an analysis of this deposit, and therefore cannot give the requisite information. The uses, however, to which diatom earth has been put are many and important, and doubtless many others will be discovered in the future. These, however, have been enumerated by Mr. H. G. Hanks, State Mineralogist, California:—

Now as to the methods to be adopted to clean and mount the diatoms in this deposit. The first thing to be done is to disintegrate the earth. This can be done (a very slow process) by soaking the earth a very long time in water and letting it crumble, and then carefully washing out the clay. A much quicker plan has been suggested by M. Parmentier, a professor of chemistry in Belgium, and was communicated by M. Guimard to the Quekett Club.^*

It consists in the supersaturation of the earth by some neutral salt, and then recrystallizing it. The crystals penetrate in every direction; then, when redissolved, the earth breaks up into a fine powder. More exactly, place a few small fragments of the earth, the size of peas, in a test-tube, and cover them to about 2 centimetres with acetate of soda, and add a

drop or two of water. The exact proportion is 5 c. centimetres of water to 100 c.c. of the salt. Heat in a water-bath. Just before reaching the boiling-point the salt will melt and be absorbed by the earth. Allow it to remain about ten minutes in the bath—a little longer will not do it any harm (I find that taking it out of the bath and giving it a good boil assists materially)—then allow it to cool. When quite cool add a fragment of the crystal acetate of soda, when the whole will immediately crystallize. Let it do so thoroughly. Then add water in excess. Heat and empty into a large and suitable vessel, and add quantities of water to wash out the acetate. I find boiling water is the best, and that the process is much facilitated by the addition of a small quantity of hydrochloric acid. If necessary the process may be repeated. It may be as well to observe that in this, as in all the other washings, the great thing is plenty of water and plenty of patience. Working at it for an hour or two a day, you will be fortunate if you have got your diatoms thoroughly clean in a week.

Many works relate various methods of cleaning diatom earth, but the methods are somewhat intricate and the directions somewhat vague. It was not until Mr. Joseph Stevens, of 18, Conference Street, Christchurch, came on a visit to Oamaru and showed us his method that we were able to work satisfactorily. And I may say I have never seen better specimens of mounting than those given me by Mr. Stevens.

Mr. Stevens's method is first boiling the disintegrated earth with strong sulphuric acid—the strongest possible. After boiling a few minutes add cautiously small quantities of chlorate of potash while boiling. The quantity of H₂SO₄ used is about twice the quantity of earth to be acted on, which must contain as little moisture as is conveniently possible. The boiling is continued until the earth becomes either brown or pitch-black, which depends on the quantity of organic matter in it, and the consequent charring or carbonising of the organic dirt. The chlorate of potash is added while boiling, to bleach the earth. (Some authors recommend permanganate of potash as being safer.) The oxygen unites with the carbon, and in a short time the blackened earth is as white as snow. This process, which is conducted in a large test-tube, is the first step, and you will succeed better by not attempting to work with too much earth at a time—a teaspoonful, or even less, is quite enough. And I would caution you to be very careful when first bringing the sulphuric acid to, a boil. Do not be in a hurry—bring it by gentle degrees to a boiling-point; for sometimes it is jumpy, and will suddenly explode out of the test-tube, to the ruin of your table, clothes, and hands. This can be entirely obviated by patience. Remember also that the

boiling-point of sulphuric acid is very high, so do not put your test-tube down in a cold place. The next step is to plunge the contents of your test-tube into a flask containing pure cold water. I use a Florence flask for this purpose, containing nearly a pint of water. Pour the boiling sulphuric acid and diatoms (safer to let it cool) into this flask. Do it carefully. It will make a noise, but will do no harm. Let your diatoms settle to the bottom, which they will do in a variable time according to their cleanliness and size (twenty minutes to two hours). You must wash them at least four times to get out the acid. The next step is boiling in an alkali. Here we must be careful and not employ too strong an alkali, neither must we boil it too long, or else your diatoms will disappear. It is true that Mr. Morland recommends boiling alternately in H₂SO₄ and strong liq. potassæ to get rid of refractory dirt in certain instances; but this is unnecessary here. The cheapest material to use is that recommended by Mr. Stevens, and that is “Hudson's extract of soap”—“washing-powder,” as used by our housewives for their clothes. We now proceed, using the Florence flask. Having washed out the acid, add a little hot water to the diatoms, and also about 10 or 20 grains of soap-extract—about as much as will cover half an inch of the large blade of your pocket-knife—and boil this—boil it till it boils freely, and stop. Let the diatoms settle. As it cools shake it occasionally to disentangle any diatoms that may be entangled in the scum, and fill the Florence flask up with pure hot water. Some of the débris, &c., removed by the soap-powder will rise to the top and some will be held in suspension by the water, the diatoms remaining at the bottom. You will now require three or four washings in pure water to get rid of your alkali, and you may now take a little up with a pipette and examine it under the microscope. You must not be disappointed if you find it still full of dirt, and sand, and débris. You may find one or two clean enough to pick off and mount, but there will not be many.

This is the whole process of cleaning so far as chemicals are concerned, and it must be repeated until under the microscope you see the diatoms are free from the minute grains of sand which spoil them. You will have to go through this process perhaps a dozen times before they are quite clean, but, having cleaned them, you will be well rewarded for your trouble.

One great difficulty is to get rid of the sand. Mr. Stevens's plan is to place the cleaned diatoms in a large circular flat-bottomed glass dish—a butter-dish or finger dessert-glass; then shake them up and rotate them as the digger does to separate his gold-dust. When rotating you will see the sand and large spicules collect in the centre at the bottom of the glass, while

your diatoms are floating in the water and flying round and round; then with an ordinary glass syringe suck up the diatoms and squirt them into another glass ready for them, when they will fall to the bottom, and may be collected again clean and free from all coarse sand.

Mr. C. Peach, of Oamaru, has devised a better and more simple plan—one which has the advantage of not running the risk of breaking the valves. Mr. Peach's plan consists in getting a triangular glass dish, which he makes by procuring a triangular piece of glass 4in. to 6in. long and 2in. to 3in. or more broad at the base and ½in. at the apex. He cements to the sides and base narrow strips of glass, about ½in. broad, leaving the mouth open. He holds this dish so that the base is lowest, and puts in a small quantity of the cleaned diatoms and sand, then shakes it gently and taps the trough gently underneath and harder at the base. The sand goes to the lowest part, and the diatoms rise and separate, flowing towards the mouth in the direction given them by the tapping. When well separated it is a very simple matter to pour them into a clean test-tube, and then, when settled down, take up and mount either as a general slide or as a selection.

Here you must remember, unless you have got rid of all the acid and all the alkali you will have trouble: firstly, the diatoms will stick to the glass so that you cannot pick them off; secondly, they will not take kindly to your mounting-medium, and you will be vexed to find them full of air-bubbles.

However, we have now got our clean diatoms. Collect some of the clean sediment in a pipette, and let a drop fall on a perfectly clean slide. Unless the glass is clean the water will not run freely in all directions, and the diatoms will not be equally distributed. You may even find that with all your trouble there is still some sand left. Well, do not mind: this is easily got rid of. Just hold the slide nearly level in your left hand, and tap, tap with the middle-finger nail of the right hand, and you will soon see all the sand collect in a mass at one edge, while the diatoms are distributed evenly all over the slide. This is one of Mr. Stevens's choicest plans, and he deserves credit for its simplicity.

Now to pick them off. You can do this slowly while it is wet by chasing any specially large diatom to the edge with a bristle, then bringing it out of the water, letting it dry, and then picking it up; but I do not recommend this plan. It may be useful for beginners, but it is a waste of time.

The proper method is to proceed as follows: The diatoms being evenly distributed and the sand at one edge, heat the slide gently over a spirit-lamp to drive off the moisture and dry the diatoms. Put on one side to cool. Then, if you have not already prepared some slides, do so in the following manner:

On the reverse side of the slide you are going to use describe a circle of ink, eitther with or without the turntable, in the centre of the glass. This ink-circle is to serve as a guide for you to place your diatoms. Dry it. Then, on the proper surface of the slide put a drop of very weak gum-water so as to cover the space occupied by the ink-circle on the other side. This gum-water must be very weak, and should be filtered; and must be fresh, or else it gets full of fungus.

I adopt a solution of arabin instead, to avoid the nuisance of having to freshly prepare the gum-water each time. The method of preparing arabin is given in the “Microtomists' Vade-mecum” (A. B. Lee). Arabin is the pure gum-extract of gum acacia or arabica, and is prepared by pouring a small quantity of thick gum-and-water into a large quantity of alcohol or spirits of wine. The arabin is insoluble in spirit, and separates as a thick, white, flocculent, opaque mass. It curdles the more as you add more spirit to it. It is then collected by filtering and drying; it is then washed in absolute alcohol and dried again: the result is a fine, pure white powder, freely soluble in water. I prepare it by adding a solution of corrosive sublimate to it, and make a strong solution, from which to make from time to time thinner solutions for use. Practice will quickly teach the proper strength. Well, having put a thin coat of arabin on the slide and dried it, we proceed to pick off our diatoms.

The best thing that I have found for this purpose is a cat's whisker fastened on a thin handle so as to leave about ⅓in. of whisker projecting. It is useful to have two or three of these, mounted with various thicknesses, for some diatoms come off easier with one than with the other.

Use a low power to examine your diatoms, and when you find one you want get it in the centre of the field and pick it up. With a little practice you will soon find that the diatom adheres very readily to the bristle or whisker. Now steadily transfer it to the centre of the dried gum. In the same way take off a few others. Now, if you wish you can arrange them in order in rows, or any design you please. Take the slide and breathe on it. This melts the gum or arabin, which runs into the diatoms. While the gum is wet you can push the diatom into any position you like, but it dries very rapidly, and then the least touch will break the diatom. If not satisfied breathe heavily again on the slide. By degrees you will arrange them as you please.

I have recommended mounting on the slide, but this is for beginners: it is much easier. Mounting on the cover-glass gives the best results, and should be the plan adopted.

However, next comes the mounting-medium. Diatoms may be mounted dry, or in some fluid medium such as Canada

balsam. If mounted dry they must be mounted on the cover and placed in a cell. Mr. Morland contributed an excellent paper on mounting-media for diatoms to the “Journal of the Quekett Club,” August, 1887. And he remarks that diatoms mounted dry cannot be examined under immersion lenses. Another medium—a saturated solution of biniodide of mercury and iodide of potassium—owing to its high refractive index, 1·68, the highest known in any aqueous solution, gives beautiful results, but it is very questionable whether it will last. “The refractive index of this medium is represented by the number 25, as compared with 11 in Canada balsam. In other words, the image is nearly two and a half times as strong.”^*

Mr. Morland, however, recommends Canada balsam as the best all-round medium. He also recommends styrax. I find this medium is generally coming into use amongst diatomists. It certainly shows up the finer diatoms and the fine markings much better than balsam. It is prepared by getting the ordinary styrax from the chemist, which, by the way, is not true styrax. True styrax has disappeared from commerce, and is replaced by “Liquidambar orientalis,” belonging to the order of the “Altingaceæ,” or else by “Liquidambar styraciflua,” from America. It is very dirty, and for use is prepared by dissolving it in pure benzole or chloroform, filtering, and then drying on a plate in a cool oven to the consistency of shellac, redissolving in benzole or chloroform, filtering twice, and then evaporating to the proper consistency. To avoid disappointment it is as well to remember that the chloroform or benzole must be pure. You will be vexed with the results given by ordinary benzole. “Jackson's” benzole is reliable and the only one to be depended on. It is, however, expensive and scarce.

A mixture of styrax and balsam has been recommended, but I have not tried it. Mr. Morland utterly condemns gum dammar. Other media have been recommended, but in the meantime I would advise Canada balsam or styrax, or a mixture of the two.

To mount the slide, warm it gently, and warm also the cover-glass: put a drop of balsam or styrax, enough for the purpose, over the diatoms, and apply the cover-glass: heat it gently, and examine to see if your specimens are free from air-bubbles; if not, heat to a greater degree, and while warm tap the slide as for the removal of sand, and you will see the air-bubbles come to the edge.

Specimens mounted in Canada balsam do not require a ring of cement, but specimens mounted in styrax must always

Plate XXIII.—

Fig. 16. Trinacria ventricosa, Gr. and St., n. sp. (Primary valve.)

" 17. " " " " (Secondary valve.)

" 18. Pseudo-rutilaria monile, Gr. and St., n. sp., n. gen.

" 19. Hemiaulus ornithocephalus (?), Grev., var. (?). (Frustule.)

[In this figure half of the adjoining valve is drawn, showing its beak-like claw or spine, by which the opposite valves are attached.]

" 20. Kittonia eláborata, Gr. and St., n. sp., n. gen.

" 21. Navicula margino-punctata, Gr. and St., n. sp.

" 22. Triceratium barbadense (?), Grev.

" 23. Aulacodiscus sollitianus, Norm., var. nova-zealandica, Gr. and St., n. var.

List of Diatoms found by Messrs. Grove and Sturt in the Diatomaceous Ooze from Cormack's Siding, Oamaru, and published in the “Quekett Journal” (alphabetically arranged).

Actinoptychus nitidus, Grun. (Heliopelta nitida, Grev.).

A. pulchellus, Grun., var. tenera.

A. simbirskianus, A. Schm.

A. splendens (Shadbolt), Ralfs.

A. (splendens, var.?) glabratus, Grun.

A. (glabratus, var.?) elegantulus, n. sp., Gr. and St.

A. undulatus, Ehr.

A. (undulatus, Ehr., var.?) constrictus, n. sp., Gr. and St.

A. vulgaris, Schum., var. maculata, n. var., Gr. and St.

A. wittianus, Janisch.

Amphipropra rugosa, Pet.

A. (?) cornuta, Chase.

Amphora cingulata, Cleve.

Amp. contracta, Grun. (var.?)

Amp. crassa, Greg.

Amp. furcata, Leud. Fort.

Amp. interlineata, n. sp., Gr. and St.

Amp. labuensis, Cleve.

Amp. obtusa, Greg.

Amp. (sp.?)

Amp. subpunctata, n. sp., Gr. and St.

Amp. tesselata, n. sp., Gr. and St.

Anaulus birostratus, Grun.

An. (?) subconstrictus, Gr. and St., n. sp.

Anthodiscus florèatus, n. sp., nov. genus, Gr. and St.

Arachnoidiscus ehrenbergii, Bail.

Arach. indicus, E.

Asterolampra decora, Grev.

Ast. marylandica, Ehr.

Ast. uraster, n. sp., Gr. and St.

Aulacodiscus amænus, Grev., var. sparso-radiata, n. var., Gr. and St.

Aulac. angulatus, Grev.

Aulac. barbadensis, Ralfs, “Pritch.”

Aulac. cellulosus, n. sp., Gr. and St.

Aulac. cellulosus, Gr. and St., var. plana.

Aulac. comterii, Arnott, var. oamaruensis, Gr. and St.

Aulac. convexus, n. sp., Gr. and St.

Aulac. crux, Ehr.

Aulac. elegans, n. sp., Gr. and St.

Aulac. huttonii, n. sp., Gr. and St.

Aulac. janischii, n. sp., Gr. and St.

Aulac. janischii, Gr. and St., var. abrupta.

Aulac. margaritaceus, Ralfs.

Aulac. margaritaceus, Ralfs, var. debyana, Gr. and St.

Aulac. margaritaceus, Ralfs, var. undosa, Gr. and St.

Aulac. radiosus, n. sp., Gr. and St.

Aulac. rattrayii, n. sp., Gr. and St.

Aulac. sollitianus, Norm., var. nova-zealandica, n. var., Gr. and St.

Aulac. spectabilis, Grev.

Auliscus barbadensis, Grev.

Aul. cælatus, Bail.

Aul. fenestratus, n. sp., Gr. and St.

Aul. grevillei, Jan.

Aul. hardmanianus, Grev.

Aul. inflatus, n. sp., Gr. and St.

Aul. lacunosus, n. sp., Gr. and St.

Aul. lineatus, n. sp., Gr. and St.

Aul. notatus, Grev.

Aul. oamaruensis, n. sp., Gr. and St.

Aul. propinquus, n. sp., Gr. and St.

Aul. pruinosus, Bail.

Aul. (pruinosus, var.?) confluens, Grun.

Aul. punctatus, Grev.

Aul. punctatus, Bail., var.

Aul. racemosus, Ralfs.

Biddulphia chinensis, Grev.

B. dissipata, n. sp., Gr. and St.

B. elegantula, Grev.

B. (?) fossa, n. sp., Gr. and St.

B. lata, n. sp., Gr. and St.

B. oamaruensis, n. sp., Gr. and St.

B. pedalis, n. sp., Gr. and St.

B. podagrosa, Grev., var.

B. punctata, Grev.

B. reticulata, Roper, forma trigona.

B. tenera, n. sp., Gr. and St.

B. tuomeyii, Bail.

B. vittata, n. sp., Gr. and St.

B. (Cerataulus ?) reversa, n. sp., Gr. and St.

Brightwellia pulchra, Grun.

Campyloneis (grevillei, var. ?) argus, Grun.

Cerataulus johnsonianus (Grev.), Cl.

Cer. marginatus, n. sp., Gr. and St.

Cer. polymorphus, Kütz., forma minor.

Cer. subangulatus, n. sp., Gr. and St.

Chætoceras gastridium (Ehr.), Grun., var.

Clavicula aspicephala, Paut.

Cocconeis barbadensis, Grev.

Coc. costatata, Greg.

Coc. naviculoides, Grev.

Coc. nodulifer, n. sp., Gr. and St.

Coc. pseudo-marginata, var. intermedia, Grun.

Coscinodiscus angulatus, Grev.

C. bulliens, A. Schm.

C. centralis, Greg.

C. concavus, Greg., nec Ehr.

C. curvatulus, Grun.

C. decrescens, Grun.

C. eccentricus, Ehr.

C. elegans, Grev.

C. elegans, Grev., var. spinifera, Gr. and St.

C. griseus, Grev., var. galopagensis, Grun.

C. inequalis, n. sp., Gr. and St.

C. kützingii, A. Schm.

C. marginatus, Ehr.

C. minor, Ehr.

C. nitidus, Greg.

C. oamaruensis, n. sp., Gr. and St.

C. oblongus, Grev.

C. oculus iridis, Ehr.

C. radiatus, Ehr.

C. radiosus, Grun.

C. rothii, Grun.

C. scintillans, Grev.

C. subtilis, Ehr.

C. subtilis, var. symbolophora, Grun.

Cosmiodiscus normanianus, Grev.

Craspedoporus elegans, n. sp., Gr. and St.

Dicladia capreolus, Ehr.

Dimeregramma fulvum (Greg.), Ralfs.

Donkinia antiqua, n. sp., Gr. and St.

Entogonia davyana, Grev.

Eunotogramma (?) bivittata, Grun. and Paut.

Eunotogramma weissei, Ehr., var. producta, n. var., Gr. and St.

Euodia janischii, Grun.

E. striata, n. sp., Gr. and St.

Gephyria incurvata, Arnott.

Glyphodesmis marginata, n. sp., Gr. and St.

Glyphodiscus scintillans, A. Schm.

Glypho. stellatus, Grev.

Goniothecium odontella, Ehr.

Grammatophora oceanica, Ehr.

Hemiaulus amplectans, n. sp., Gr. and St.

Hem. amplectans, var. major, n. sp., Gr. and St.

Hem. angustus, Grev.

Hem. barbadensis, Grun.

Hem. dissimilis, n. sp., Gr. and St.

Hem. includens (Ehr.), Grun.

Hem. lyriformis, Grev.

Hem. ornithocephalus, Grev.

Hem. polymorphus, Grun.

Hem. (?) tenuicornis, Grev.

Hyalodiscus arcticus, Grun.

Hyal. radiatus (O'Meara), Grun.

Hyal. subtilis, Bail.

Huttonia alternans, n. gen., n. sp., Gr. and St.

Hutt. virgata, n. gen., n. sp., Gr. and St.

Isthmia enervis, Ehr.

Kittonia elaborata, n. gen., n. sp., Gr. and St.

Kitt. virgata, n. gen., n. sp., Gr. and St.

Lampriscus (?) debyii, n. sp., Gr. and St.

Liradiscus ovalis, Grev.

Mastogloia reticulata, Grun.

Melosira borreri, W. S.

Mel. clavigera, Grun.

Mel. oamaruensis, n. sp., Gr. and St.

Mel. sol, (Ehr.), Kütz.

Mel. westii, W. S.

Nitzschia antiqua, n. sp., Gr. and St.

Nit. grundlerii, Grun.

Navicula apis, Ehr.

Nav. biconstricta, n. sp., Gr. and St.

Nav. braziliensis, Grun.

Nav. decora, n. sp., Gr. and St.

Nav. definita, n. sp., Gr. and St.

Nav. dispersa, n. sp., Gr. and St.

Nav. gemmata, Grev.

Nav. (Alloneis ?) grundlerii, Cleve and Grun.

Nav. inelegans, n. sp., Gr. and St.

Nav. interlineata, n. sp., Gr. and St.

Nav. margino-lineata, n. sp., Gr. and St.

Nav. margino-punctata, n. sp., Gr. and St.

Nav. placita, n. sp., Gr. and St.

Nav. prætexta, Ehr.

Nav. sandriana, Grun.

Nav. smithii, var. nitescens, Greg.

Nav. sparsipunctata, n. sp., Gr. and St.

Nav. spathifera, n. sp., Gr. and St.

Nav. trilineata, n. sp., Gr. and St.

Orthoneis splendida (Greg.), Grun.

Paralia sulcata (Ehr.), Cleve (Orthorisa marina, “S.B.D.”).

Plagiogramma (constrictum, var?) nancoorense, Grun.

Plag. neogradense, Pautocsek.

Plag. tesselatum, Grev.

Podosira hormoides (Mont.), Grun.

Pod. maxima, Kütz.

Porodiscus hirsutus, n. sp., Gr. and St.

Por. interruptus, n. sp., Gr. and St.

Pseudo-rutilaria monile, n. sub-gen., n. sp., Gr. and St.

Pyxidicula cruciata, Ehr.

Pyxilla dubia, Grun.

Pyx. johnsoniana, Grev.

Pyx. reticulata, n. sp., Gr. and St.

Pyx. (?) (Pterotheca, Kitt.) aculeifera, Grun.

Rutilaria epsilon, Grev.

Rut. epsilon, var. tenuis, n. sp., Gr. and St.

Rut. lanceolata, n. sp., Gr. and St.

Rut. radiata, n. sp., Gr. and St.

Stephanogonia danica (Kitt.), Grun., var.

Stephanopyxis barbadensis (Grev.), Grun.

St. ferox (Grev.), Grun.

St. grunnowii, n. sp., Gr. and St.

St. turris (Grev.), Grun.

St. turris, var. brevispina, Grun. (And numerous other forms belonging to Stephanopyxis.)

Stictodesmis australis, Grev.

Stictodiscus californicus, Grev., var. areolata, Grun.

Stict. californicus, var. nitida, n. var., Gr. and St.

Stict. hardmanianus, Grev., var. megapora, n. var., Gr. and St.

Stoschia (?) punctata, n. sp., Gr. and St.

Synedra crystallina (Ag.), Kütz.

Terpsinoe americana, Bail.

Terpsinoe americana, Bail., forma trigona, Pautoc.

Triceratium americanum, Ralfs.

T. americanum, var. quadrata, n. var., Gr. and St.

T. arcticum, Bright.

T. arcticum, var. permagnum, Janisch.

T. arcticum, Brightw., forma quinquelobata.

T. ausliscoides, n. sp., Gr. and St.

T. barbadense, Grev.

T. bimarginatum, n. sp., Gr. and St.

T. capitatum, Ralfs.

T. castellatum, West.

T. concinnum, Grev.

T. condecorum, Ehr.

T. cordiferum, n. sp., Gr. and St.

T. coscinoide, n. sp., Gr. and St.

T. coscinoide, var. quadrata, n. sp., Gr. and St.

T. crenulatum, n. sp., Gr. and St.

T. crenulatum, forma gibbosa, n. sp., Gr. and St.

T. denticulatum, Grev.

T. divisum, Grun.

T. dobreèanum, Grev., var. nov.-zealandica, n. var., Gr. and St.

T. eccentricum, n. sp., Gr. and St.

T. exornatum, Grev.

T. favus, Ehr.

T. favus, var. quadrata, Grun.

T. favus, (Ehr.), var. pentagona.

T. grande, Brightw.

T. grande (B.), forma quadrata.

T. harrisonianum, Norm. and Grev.

T. inelegans, Grev., var.

T. intermedium, n. sp., Gr. and St.

T. kinkerianum, Witt.

T. lineatum, Grev.

T. lineatum with two processes, Grev., var.

T. lobatum, Grev.

T. montereyii, Brightw.

T. morlandii, n. sp., Gr. and St.

T. neglectum, Grev.

T. nitescens, Grev.

T. oamaruense, n. sp., Gr. and St.

T. obesum, Grev.

T. papillatum, n. sp., Gr. and St.

T. parallelum (Ehr.), Grev., forma trigona, A. Schm.

T. parallelum, forma trigona, var. gibbosa, Gr. and St.

T. parallelum, forma quadrata = Amphitetras parallelum (Ehr.), Grev.

T. plumosum, Grev.

T. pseudo-nervatum, n. sp., Gr. and St.

T. rectangulare, n. sp., Gr. and St.

T. repletum, Grev.

T. rotundatum, Grev.

T. rugosum, n. sp., Gr. and St.

T. sexapartitum, n. sp., Gr. and St.

T. shadboltianum, Grev.

T. spinosum, Bail., var. ornata, n. var., Gr. and St.

T. stokesianum, Grev.

destroy them, unless we admit that the natives at a comparatively recent time assisted in their extermination, thereby hastening the final disappearance of a group of dinornic birds, which had inhabited an isolated land-area of limited extent for such a length of time as sufficed for the development of at least twenty well-defined forms or species, a large proportion of which it will be seen were co-existent in this district.

Mr. Park, in the Geological Reports for 1887,^* gives an instance of the finding of bird-bones in the brown sands near Kai-iwi, Wanganui, by Mr. Drew, an energetic collector in that district; and goes on to say, “On examination they were identified as belonging to the latter” (small moa). This, I believe, is the first discovery of fossil moa-bones in New Zealand. When I arrived in Napier some years ago, Mr. F. Williams kindly showed me a block of sandy clay containing a well-preserved femur of a moa, and also several fragments of bone and some large pieces of egg-shells, all from one locality. He stated that they had been dug out of a cliff on the shore of the Inner Harbour, at an island called Te Ihu te Otere. These specimens were then sent to the Colonial Museum, at Wellington, where I saw them a short time ago. I visited the place where the bones were found soon afterwards, and succeeded in finding several fragments of bone and plenty of egg-shell.

The bones are found in the face of a high cliff formed of the Petane marls, and lie, together with a few large pebbles or shingle, at the bottom of a small valley of denudation which has been filled in by subaerial formation similar to the Petane clay and sand, containing fragments (blown?) of Pecten novæ zealandiæ and great numbers of two small land-shells, Therasia thaisa and Helix rotundata. This filled-up valley has been cut through at right angles by the denuding action of the waves, which has determined the present coast-line of the harbour and bay. The height from the top of the cliff to the bottom of the synclinal trough thus exposed is about 90ft., a few feet at the top of the cliff being the prevalent superficial pumice of the district, and which caps most of the high country.

At one of my visits to this interesting locality I found a large block had fallen to the sea-level or beach (which is here about 10ft. or 12ft. below the moa-bones), and on one face of it I found a small femur which corresponds exactly with the figure given by Owen of that of Notornis mantelli: this I dug out carefully, and it is now in our Museum. Nearer the surface of the water, where the boring crustaceans had begun to riddle the block, I saw traces of egg-shell, and, examining it

more closely, found that there were two regular layers extending over a considerable distance. Having cut out a large piece of the block, I brought it home, and you can now see on the table before you a fossil moa's egg. The egg has evidently been flattened, and thus shows two layers of shell extending all round the block more or less continuously.

Owing to the nature of the cliff it is impossible to make any further excavation in this place, although many fragments of bone and bits of egg-shell indicate that the bottom of this old gully yet contains many bones.

The Marine Parade of Napier does not seem a very likely place for moa-bones, but at the end of the Coote Road the sea cuts into a deposit of brick earth or loëss, which abuts sharply against the Limestone Bluff. The upper part of the section exposed is full of débris from the Bluff Hill; but below this, and more towards the steps, bird-bones of various sizes are occasionally to be found, and sometimes a moa-bone. I had the pleasure of showing one in sitû to Dr. Hector when he was here in 1878: since then several have been exposed. I have seen one within the last month. At the foot of the hills between Pakipaki and Mr. Douglass's station are some very deep creeks, coming from the limestone hills and cutting through slope-deposits and flood-silts. In one of these creeks I obtained about a dozen good moa-bones. In a valley of the Greenmeadows Estate, close by the Puketapu road-cutting, a large number of moa-bones in a very fragmentary condition were found when the swamp was drained and the ground first broken up. I was fortunate enough to get a few good bones of a small species of moa and some bones of the extinct eagle (Harpagornis).

Another very interesting locality, about which I hope to have something to say some day in detail, is the sea-beach near the woolshed at Waimarama. Here the beach is often swept of the sand by the waves right down to the blue clay, in which are seen stumps and roots of trees and moa-bones. Mr. Hill and I, the last time we rode by there, saw about half an acre of blue clay thickly studded with bones, all in too rotten a state to bear removal. Many bones have been got from the creek which here runs into the sea.

I have dug out a stout femur from the cliff on the north side of the Waikare River, near Mohaka; and in the Museum are four very fine bones which were found in the Poutou Creek, in the same neighbourhood.

This brings us to surface-finds, and here I must note some very large but much-decayed bones found by Dr. Hector in the Raukawa Bush, now in our Museum. They were found on the surface, but all the small bones had disappeared. Mr. Pine, of Raukawa, and myself found several good moa-bones in a creek

which drains a large swampy valley near the Raukawa Station, and I am in hopes that some day a large deposit of bones may be found there.

Away up the Tutaekuri River is a large tributary called the Mangahone. Here one of our members, Mr. Taylor White, has found some more or less perfect bones. Still further up the same river, at Glenross, Mr. Balfour has sent us down moa-cropstones and bones of kiwi and moa. Several bones have been picked up from time to time in the bed of the Petane River, and a femur and two or three vertebræ were dug from a small swamp close by the Petane School.

One rather interesting find was a tibia found by me just at the edge of the bush at Takapau. The bone was in the bed of a small creek, and, though in good preservation, one-half was thickly covered with moss.

With the exception of the last-mentioned and the bones from the Poutou Creek, all the bones recorded were too imperfect to be of much use; but, fortunately, others have been found in a most exceptional state of preservation and of great scientific interest. One day I was shown a very fine tibia which had been found at Patangata: this was in the possession of a gentleman at Waipawa. I then saw an equally good one in the possession of our President from the same neighbourhood, and on further inquiry heard that a large number of bones had been found during the works which were being carried out for the drainage of the Te Aute Lake. The Rev. S. Williams (now Archdeacon of Hawke's Bay) very kindly allowed me to examine the bones which had been preserved, which I found indicated the occurrence of a large number of moas, many of them of gigantic size, the length of one tibia being 37½in., only a trifle short of the largest specimen hitherto recorded. During the last summer the progress of the great drain enabled me to examine the locality carefully, and, through the courtesy and kindness of the Rev. S. Williams and Mr. Allan Williams, I was able to secure a most interesting collection of bones, some of which are now before you. The spot where the bones were found is at the south-east end of the large tract of swampy land which surrounds the lake. The overflow from this area, which was frequently flooded to a considerable depth by a channel cut by the Waipawa River, was carried off by a small creek or stream which rejoined the main river at Patangata. A deep channel was blasted through a bar of limestone rock which formed the end of a low ridge of hills forming the eastern boundary of the swamp. By lowering this outfall and cutting a great drain nearly two miles long, the whole of the swamp has become passable, and will shortly be carrying a very large number of cattle and sheep.

Mr. Allan Williams kindly took me to the drain, and the

foreman showed me the place where the bones had been found most plentifully. A slight examination showed that there were plenty more bones to be got. I decided on excavating for them.

The spot where the bones were found is just at the very mouth of the drain, where it empties itself into a very deep pool, of which the rock-barrier forms the further side. The section exposed in the cutting of the drain is about 15ft. deep, and is 8ft. or 10ft. of silt-deposit (pumice and washing from the cretaceous rocks of the district): then a forest-bed, consisting of trunks of trees and roots matted together—about 4ft.; from that downwards a stiff blue clay. It is in the lowest part of the forest-bed and in the stiff blue clay that the bones were found.

The line of the drain has passed over'a spring round which the blue clay is so soft that it was impossible to stand very near to it.

I had two of the men who were working at the drain to help me, and we got quite interested in the work, as we found that in the clay under our feet at the bottom of the drain there were hundreds of bones. Having to work up to our middle in clay and water was certainly somewhat awkward; but, as every now and then an exceptionally fine bone was fished up, the discomfort was forgotten. The floor of the drain was not more than 10ft. wide, and, as the area over which we found the bones did not extend more than 15ft. up the drain, the number of bones recovered is certainly remarkable.

The appliances we had did not permit of as careful an examination as I could have wished, as many of the valuable small bones were undoubtedly lost and thrown down the talus slope into the deep pool, where there are undoubtedly many more, as we found out by accident. One of the shovels having slipped into the pool, we raked about for it as far down as we could put a long-handled rake, and at the first haul, instead of the shovel, up came a splendid tibia 32in. long. I hope to dredge this hole some day, and by washing the results through a screen shall probably get many of the smaller bones which I still require to complete the skeleton I am now restoring from the bones obtained.

It was from the first apparent that (as in the case of the Glenmark and Hamilton finds) no perfect skeletons would be met with, and I could observe very little sequence or order in the manner in which the bones were found deposited, the only point of interest being that most of the larger leg-bones were found in a vertical position, the tibia and metatarsus often in their relative positions. A sequence of eleven vertebræ of a large species was found in one part of the bank; but generally speaking the bones, great and small, were locked

together in great confusion. The men who assisted me were very careful in extricating the specimens, and very few were injured considering the difficulty of working under water, and in the stiff and extremely tenacious clay.

After two days' work at this place, and an examination of two places higher up the drain where a few bones had been found, we ceased operations.

Mr. Williams kindly had the spoils conveyed to the station, and the railway authorities kindly conveyed the bones to Napier free of charge.

The bones which I have referred to as having been got on the first cutting of the drain were also presented by the Archdeacon to the Museum, and sent down to Napier.

The cleaning, sorting, measuring, comparison, classing, and identification of more than a thousand bones and fragments has necessarily taken me some time, and I regret that I shall have to leave what will perhaps be the more interesting part of my paper till another occasion, on which I hope to enumerate the kinds and relative bulk of the species met with, and to draw your attention to the more striking features in the anatomy of the gigantic moas.

It may possibly be asked how can such an accumulation of bones in the one place be accounted for. This I hope to give a reasonable theory for in the next paper. At present the facts lead me to the conclusion that the most tenable hypothesis is that the spot was a narrow crossing-place in a swampy forest, and that the springs caused the ground to be so soft and swampy that moas were often bogged and unable to extricate themselves. The reasons in support of this I shall advance for your consideration.

P.S.—Within the last few days I hear that another find of moa-bones has been made in the same swamp. If such is the case I trust that the new discoveries will enable us to complete our series of the North Island forms of Dinornis.

In the notes which I had the honour to read to you at the July meeting, I gave some account of the deposit of moa-bones examined by me at Te Aute, and promised to continue the paper.

Just before our last meeting I paid another visit to the lake, and found that another discovery had been made in a spot nearly two miles from the original find.

It seems that when the drainage operations reached the actual shore of the lake itself the drain was continued in a straight line nearly half a mile into the lake, passing through the centre of an irregular winding lagoon forming the exit of the lake. The result of this was an immediate lowering of

the water in the lake, and the laying-bare of the whole of the winding lagoon, which was then seen to consist of a matted network of forest-roots and timber, together with innumerable seeds of hinau and manuka.

Lying on and among the roots were quantities of bones, which the foreman of the works, Mr. Pickett, carefully collected for me, and which prove of surpassing interest.

The bones were, as in the former case, nearly all in one small area, and, strange to say, just at the foot of a spur, as in the first find; but here they were lying on the surface, and were in a most wonderful state of preservation, young and old, great and small. One bone, an immature tibia, measures 35½in. The bones of the moas are in, as I said, a wonderful state of preservation; but by far the most interesting are the small bones which have been disclosed by this lowering of the water.

Although my identifications are not yet complete, I have got bones of the great extinct goose—the Cnemiornis—a breastbone quite perfect, the bones of the legs, and some of the wing-bones. In general, these bones are smaller than those found in the South Island.

Of the great extinct eagle (Harpagornis) I have several bones—amongst others an ungual phalanx, or claw-bone, and several tibiæ. This is extremely interesting, as I did not meet with this species in the other deposit.

The next treasure is a perfect lower mandible of Notornis. This gigantic rail can therefore be undoubtedly added to our list of Te Aute birds. I show you the life-sized drawing made from the specimen obtained by Mr. Mantell, now stuffed, and placed in the British Museum.

Many other bones occur, which I have not yet been able to recognise. There are three or four tibiæ (immature) of a large wading-bird as large as our white heron, or kotuku.

At the time of my visit the spot itself where the bones were found was under water, owing to the lake being filled up with the rain; but I could see the higher parts of the stumps and roots above water. On the level muddy floor of the lake, some chains from the edge, a very large pelvis was found quite exposed.

Without further investigation it would be rash to conclude that these bones are very recent. I think it more probable that they are of the same age as the bones at the rock, but that the action of the flowing water from the lake has removed the accumulation of vegetable matter in which they were buried, and left the bones entangled among the roots and timber.

Two points may be noticed in connection with this discovery:—

having found in it many varieties of fossil leaves, and it was then referred to by me as corresponding to the Kidnappers conglomerate and pumice-beds, which, in my opinion, form the youngest of the pliocene deposits in this district.

Professor Hutton, in vol. iv. of the “Transactions,” gives a description and an illustration of a moa-feather, and in several particulars two of the feathers found by me in the above beds agree with the description referred to. Unfortunately, the top ends of two of the best specimens are missing. The feathers are about 4in. long, and the barbs are unconnected, as in the case of struthious birds. The barbules can be seen, but there are no other traces of bifurcations, nor is there any accessory plume, as in the case of many specimens of moa-feathers now known. The feathers differ from any of the illustrations in the “Transactions” in their being broader, in the basal part of the shaft being thicker, and possibly in the absence of barbs at the basal end, these not showing at the point where the shaft is broadest.

The other feather which I have is not such a perfect specimen as the above, and it appears to be of a different kind. It is about 2½in. in length, and is bent not unlike the small side-feathers to be seen in the Prince of Wales plume.

I do not think there can be any doubt as to the feathers here described having once belonged to a moa, and if such be the case it will place the history of that bird much further back in geological time than has hitherto been recognised. No scientific question has been more sturdily discussed in our “Transactions” and elsewhere than the date of the disappearance of the moa in New Zealand, one party maintaining that the moa has been so long extinct that no reliable traditions have been handed down, whilst yet another party supports the view that the moa became extinct in comparatively recent times. The case, however, is yet undecided, and we must wait for further evidence on this interesting subject before a final judgment can be entered. But in the long discussion which has been carried on no one, as far as I am aware, has hitherto produced any evidence likely to call in question the statement put forth by the late Sir Julius von Haast to the effect that “different species of Dinornis or moa began to appear and flourish in the post-pliocene period of New Zealand.”^* The generalisation made by Sir Julius was based upon a wide experience and knowledge of the remains of moas found throughout the country, but it would seem to have been made without due consideration as to what the future testimony of the rocks might be on the subject.

The discovery of fossil feathers in pliocene beds offers suffi-

miles from Gisborne in a north-west direction, and at a height of about 450ft. above sea-level. The well belonging to the former company is situated on the Wairangamea Stream, five miles above its junction with the Waipaoa River, which empties its waters into Poverty Bay. The Minerva well is situated on the Waipaoa River, a mile or so to the west of the Pacific Company's well. Work had been stopped at the Pacific Company's well at the date of my visit, but I was enabled nevertheless to gather a good deal of information from the gentleman in charge, who is an experienced American well-sinker. As already remarked, the engine-house and derrick at this well had been destroyed, and in order to provide against further accidents a cap had been fixed on the pipe or tube-bore of the well, and this was kept locked. This cap was taken off, and I saw for the first time an oil-well, having a pipe or tube 6in. in diameter, and passing down into the earth more than 1,300ft., and as far as one could judge it was full of oil to the brim. Specimens of the oil were obtained by me, and I have no doubt whatever that they are genuine.

The oil appears of a grey-amber colour when held against the light, and its specific gravity in its crude state is greater than the American oil. As to its illuminating qualities, it is impossible to speak with certainty, but the tests hitherto made have been very satisfactory. The exact depth of the well is 1,321ft. This is the depth at which oil has been struck, so that the oil-rock or oil-beds are about 870ft. below sea-level. The oil in the tube rises 3ft. or so above the surface, but, curiously, the height varies according to the direction of the winds and the character of the tides. Before the great eruption at Tarawera when the terraces were destroyed it was noticed that one of the great cauldrons of boiling water varied in its intensity according to the direction of the winds, and we know as a fact that the artesian wells in Hawke's Bay rise about 2ft. higher at high tide than at low tide. It hardly seems credible that wells—and those oil-wells—so far from the sea could be influenced by the action of the tides, as is the case with our local artesian wells; but such would appear to be the case: this could only be possible, as far as I can judge, on the supposition that the oil-bearing strata are similar in arrangement and plan to an artesian basin.

When the explosion took place in the well under notice the tools were lost, and they have remained in the well ever since. When the machinery is once more in working-order, and the tools have been recovered, it may be that the boring-tool will be able to penetrate still further into the oil-bearing strata, and that the flow will be largely increased; for unless the well be a flowing one I do not see how it is possible to make it a paying concern, which, after all, is the practical test

of the capitalists. The sinking at the Minerva well has not reached more than 750ft., but the prospects are reported as being good, and the working manager anticipates reaching the oil-beds at 1,000ft., or 1,100ft. at the furthest. I fear the manager is too sanguine on this point; but in any case the working of this second well, and of a third well midway between the Minerva and Pacific Company's wells, will provide data of great importance as to the dip and character of the oil-bearing strata along the east coast. At present everything in connection with the oil industry is tentative. Facts have to be gathered together and careful observations made before inferences can be drawn as to the future success of the east coast as an oil-producing district. But the subject is of special interest to this colony, for the question as to the employment of petroleum as a fuel is growing into prominence every day, and I look upon it that no opportunity should be lost by the Government in providing for the accumulation of facts and statistics bearing on the question of sinking and the production of oil, which might prove of great value in the near future.

The east coast district north of the Kidnappers is mainly composed of rocks of tertiary age, and it is among the tertiary rocks that evidence is forthcoming as to the existence of oil.

In America the oil is found in the silurian rocks; but in Burmah, in Galicia, in Austria, in France, and in the celebrated district south of the Caucasus, the oil is found in rocks of tertiary age, as in this country.

As far as I can judge from the sections (see Plate XXIV.), the sinking at the South Pacific well shows no rocks except tertiary; but it is a curious circumstance that what are known in the American oil-fields as the first, second, and third sand-rocks are reported as having been passed through in the South Pacific well, and latterly in the Minerva well. These sand-rocks vary in structure, depth, and thickness in the different localities of the American oil-regions, but from each bore oil is obtainable, the best flow, though not the most valuable oil, being in the third or lowest sand-rock. The manager of the South Pacific well has had an extensive experience in America, but he is no doubt mistaken, notwithstanding, as to the similarity between the sand or oil-producing beds in America and the rocks passed through in this country. There may be some likeness between the sand-rocks, or what are called sand-rocks by some oil-sinkers, in America and in the Poverty Bay district; but in America the sand-rock is the true oil-bearing rock, whilst in the South Pacific well, according to the sections shown on the manager's plan, the so-called sand-rocks simply

gave a show of gas and oil where passing through them, and oil has been struck 170ft. below the third sand-rock, as shown by him. No instance, as far as I am aware, has as yet been found of oil below the third sand-rock.

Between the American oil-wells and that sunk by the South Pacific Company there is one point of similarity worthy of special notice. In all the American wells brackish or salt water is found immediately overlying or in connection with the oil. The two liquids have been found in almost immediate contact very generally in the first, second, and third sandstone (?), the rule being in some districts “No brine, no petroleum,” for while the brine usually manifests itself first in order when the pump is applied, it never forsakes the oil; the two clinging to each other like brother and sister. I understand that similar appearances are met with in Burma and in Galicia, but whether they occur in France or in the district south of the Caucasus I have been unable to ascertain.

At the South Pacific well salt water was everywhere met with below 470ft., so that in this particular the appearances are encouraging. The existence of brackish water along with oil is of great interest as probably giving a clue to the extent of the oil - bearing strata along the east coast. I have watched for a long time past, as opportunity offered, a number of salt springs which are to be found scattered over a large extent of country extending from the Mahia Peninsula to Poverty Bay, and thence onward north-west or north-northwest in the direction of the oil-wells. These springs resemble miniature volcanic cones, the crater being occupied by water and mud instead of lava. This water rises and falls as the gas-bubbles rise to the surface, and the bursting of the bubbles causes a bluish-grey mud to be thrown out, which forms a conical mound of bare ground. The gas-bubbles explode if a lighted taper is held over the surface of the water just as they rise to the top. At Tua Motu, near Gisborne, and on what is known as the Kaiti Block, the springs are somewhat numerous; and inland, some miles to the west of Wangara, fifteen miles or so north of Gisborne, very large salt springs are met with.

The appearances observable in the oil-fields of different localities and countries may prove by comparison of great value in discussing the prospects of the east coast as an oil-producing district. Surface-appearances may not afford proof positive that payable oil will be struck, nor is it to be expected that they should; but they may be indicative, nevertheless, of similar causes operating to produce the appearances: and it seems to me that the origin of the oil may by this means be inferred. Many theories have been put forth as to the origin of oil, one being that it results from the distillation of vegetable remains not yet turned into coal, another that it

is produced from the destructive distillation of coal, another that it is derived from the animal remains collected at the bottom of seas; whilst latterly a chemist has put forth the theory that oil is purely a mineral product, that it is due to the action of water on masses of carburets of metal, chiefly iron, at high temperatures far down in the earth, and that its production is going on day by day.

It is well known, however, that oil is found in the tertiary rocks in close connection with lines of volcanic phenomena. In the oil-region of Burma mud-volcanoes and hot springs are met with in close proximity to the oil, and it is certain that similar phenomena have been seen to the south of the Caucasus, between Baku and Tiflis, since the days of Marco Polo, who in his book of travel refers to a well of flowing oil suitable for use as lamp-oil.

Now, there are hot springs and mud-cones within the limits of the oil-wells of the east coast district; and, although these may probably exist in the absence of an oil-field, they still form what may be termed very favourable indications as far as the district under notice is concerned. But the indications grow in importance in face of the fact that oil has been struck; and the time may not be distant when the position of hot springs, salt springs, and mud-cones may become of commercial importance, for the reason that wherever the salt springs and mud-cones are found the rocks are identical with those where the oil-wells are situated. It is true that the country north of the Mahia Peninsula is rough and broken in places, and great flexures are to be met with on the coast to the north of Poverty Bay; but I see no reason why oil should not exist in basins as in the case of artesian wells, and flow accordingly. I am aware that flowing oil-wells are supposed to be due not to hydrostatic pressure, like an artesian well, but rather to the elastic force of the gas (carburetted hydrogen) which accompanies the oil in the majority of the wells; but this does not appear to be essential in the case of all flowing wells, and it is clear that some flowing wells must be due to hydrostatic pressure.

The east coast oil-district is surrounded by enormous beds of porous fossiliferous sandstones, which trough under Poverty Bay and underlie all the younger tertiaries, and it may be that these sandstones are the oil-bearing rocks of the district. At present, however, the data available are not sufficient to affirm with any degree of certainty either the character of the oil-beds or the actual existence of a payable oil-field; but, still, the prospects are encouraging and are worthy of careful attention even from a geological standpoint. The Minerva well is now within 300ft. of the oil-bearing strata, and another well is being put down at the point where the

The age of our coal presents a marked distinction from that of the great coal-deposits of England, continental Europe, and North America, which occur in strata lying between the Old and New Red Sandstones. In the early part of this century so imbued were geologists with the idea that true coals were confined to this horizon that the coal-bearing strata received the age-name “Carboniferous,” which is now generally applied to all rocks of this period, whether they contain carbonaceous deposits or not.

The subsequent discoveries of true coal in Lower Secondary strata in New South Wales, in Jurassic strata in India, and Upper Secondary strata in New Zealand, conclusively showed that, given the necessary geological conditions, coal could be formed at any period of the earth's history. Up to the present time no coal-seams have been found in rocks below the Devonian, and from this circumstance it is argued by some scientists that there must have been a scarcity of carbonic acid on the earth's surface prior to this period—too little, in fact, to favour the growth of great forests or dense vegetation of any kind. However true this may be of the Old World, it certainly does not apply to New Zealand. Among the Silurian schists and marbles of Western Otago, which are simply altered sandstones and limestones, there occur layers and nests of graphite under conditions which leave little room for doubt that they are the product of altered carbonaceous matter of vegetable origin.

It is now generally admitted that all coals rest on old soils or land-surfaces, and consist of nothing but vegetable matter. Judging from the leaf-impressions in the coal-shales, it is probable that our coals are principally the result of forest-vegetation of long-continued growth, among which dicotyledons are largely represented, and after these cycads, conifers, and ferns.

With one or two exceptions, the coal-deposits of this country occur near the base of the measures, which generally rest on the basement-rock of the district, showing that the forests grew on a long-persistent and comparatively stationary surface, with perhaps in most cases a tendency to a downward movement. After a period of rest, during which the carbonaceous matter accumulated, the land began to sink, and from the character of the estuarine and marine strata which cover the coal it can be ascertained that these old forests flourished on low-lying areas contiguous to the sea, or in deep estuaries or bays to which the sea had free access. The marginal or littoral character of our coal-areas can be seen at a glance by looking at the mineral map of New Zealand issued with the Geological Reports for 1886–87.

As a result of our coals having been formed on old land-

surfaces, the seams necessarily partake of all the irregularities of the land, and are consequently subject to great variations of thickness along the line of outcrop. It is also noticeable that where the land is steep the seams thin out rapidly to the dip.

It is a remarkable fact that, although the workable coals of New Zealand are all of the same age, they differ widely in their mineral characters and composition: for example, those of Otago are hydrated brown varieties, sometimes little better than lignites, while those of the west coast of the South Island are anhydrous or bituminous coals, mostly of fine quality, and in some respects superior to the coals from New South Wales. It should be stated, however, that the different varieties shade into each other: thus we have brown coals which exhibit an approach to semi-bituminous coals, which in their turn merge into true bituminous or caking-coals.

It would be difficult to define a dynamic agency competent to produce the metamorphism of the coals of the Grey and Buller coalfields, and at the same time so exclusive as to restrict its operations to these areas.

When this interesting question receives more attention, it will, I think, be found that the quality of the coal is largely influenced by the character of the enclosing strata: thus, when the measures are loose and porous the decomposition of the vegetable matter will probably result in the formation of lignites or hydrous brown coals, such as those of Otago; when greensands of a less pervious nature, a better class of coal will be formed, of which examples may be found at the Mokau, Waipu, Whangarei, and Kawakawa coalfields; and when heavy deposits of impervious fireclays, the result will be bituminous coals.

As the result of a large number of analyses in the Colonial Laboratory, Dr. Hector in 1872 classified the coals of New Zealand as follows:—

I. Hydrous (coal containing from 6 to 20 per cent. of permanent water)—

II. Anhydrous (coal containing less than 6 per cent. of water)—

The workable coals come under three principal divisions—namely, (1) brown coal, (2) pitch-coal, and (3) bituminous coal. These varieties are distributed in what may be termed

geographical areas of deposition; thus, the brown coals occur principally in the eastern portion of the great axial division of the South Island, the bituminous coals in the west coast district of Nelson, and the pitch-coals in the North Island.

In preparing the following estimate of workable coal I have not included lignites, nor coals of any kind where the thickness of the seams is less than 2ft. These will no doubt be of great importance when the coalfields become exhausted; but until then they will have no market-value, and will probably be little sought for except for purely local consumption where other kinds of fuel are scarce:—

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After all necessary deductions for losses in working, &c., the total quantity of available coal may be set down at a thousand millions of tons, which at the present market-value of coal would represent about £750,000,000.

Until actual surveys are made, the above figures must only be looked upon as approximate estimates, but in most cases they are well within the mark. Most of the coal is level-free, and only such seams as are workable at the present time have been included in these returns. Ample allowances have also been made for areas of coal removed by denudation.

In addition to the coalfields mentioned in the above tables, small patches of coal-bearing measures occur at Takaka, Baton, Tiraumea, Karamea, and Lyell Mountains, in Nelson; at Waihaoa and Waipara, in Canterbury; and at Preservation Inlet in Otago.

Several thin seams of bituminous coal, ranging from a few inches to 15in. in thickness, occur in Jurassic rocks at the Hokonui Range, Waikawa, and Mataura. At the two former places prospecting operations were at one time undertaken to prove the extent of the coal, and quite recently a bore 131ft. deep has been put down at Rocklands, near Fortrose, with the same object. The seams in this formation are everywhere too thin to work, and, judging from the rapidly-alternating character of the strata, the land-movements at this period were too frequent to permit of the accumulation of large carbonaceous deposits, and for this cause little hope can be held out of thicker seams being found at these places.

Having determined the probable quantity of coal contained in our coalfields, we now arrive at the important problem,

How long may such quantity of coal be reasonably expected to last?

If we turn to the records of our output since 1878, we shall find that the total quantity of coal raised in the colony in that year was 162,218 tons, and in 1881 337,262 tons, which is equal to an increase of 100 per cent. in three years. During the last seven years the growth of the output has been slower, and shows something of a geometrical or proportional rate of increase.

The latest and highest recorded output—that of 1887, amounting to 558,620 tons—bears but a small proportion to our vast stores of coal, which in fact contain the former 2,181 times. But a little consideration will show that it would be absurd to speak as if we had enough coal to last for more than two thousand years, since the present rate of consumption is not a fixed but a growing rate.

The production of coal in Great Britain in 1887, according to the reports of the Inspectors of Mines, was 162,119,812 tons, which is contained in the total estimated available quantity of coal—amounting to 146,480,285,398 tons, as determined by the Royal Coal Commission in 1866—no less than 903 times. With this material it has been estimated by various authorities that the coal of Great Britain must be exhausted at periods ranging from eighty to one hundred and fifty years from the present time.

In New Zealand the coal industry is still in its infancy, and it is in consequence impossible at the present stage of our output to determine whether the rate of our increase is geometrical or arithmetical.

It is obvious that the output is governed by two causes—first, the natural increase of our population, and, second, the growth of capital applied to the development and extension of our manufactures.

Starting from the actual output in 1887, the output at intervals of ten years up to 1957 would be as follows—assuming that the increase of output continues uniform with the average yearly increase for the last seven years, which is sufficiently near for our purpose:—

On the assumption that the facts of the past seven years supply adequate indications of the law of consumption of the

and the large amount of débris carried by the ice in this glacial epoch, will well account for the wearing-power we see in the ranges of mountains, in the vast accumulations and the different varieties of rocks and soils that fill our valleys, and in the equally extensive appearance of flowing water that has so fully sorted them during their deposition.

To-day we observe in valleys running east and west very strong evidence of their shady and sunny sides in the difference in the growth of vegetable life; and in the glacial epoch this difference between the shady and sunny sides I imagine to be equally observable. The shady side, facing the south, would be the last home of the glaciers, and thus account for the greater quantity of deposit which we call the terraces of to-day; whilst the sunny side, facing the north, being more under the influence of water caused by the melting snow, has been scoured out, and has thus prevented the débris being of equal height on both sides of such valleys. Every valley thus tells its own geological story, a large one like the Clutha or Molyneux Valley having, of course, more to tell us than its smaller companions.

When considering this subject we must bear well in mind the difference between the very gradual melting of snow and the more powerful water-scouring of our present rainfall—sometimes light, sometimes heavy, especially during tropical and thunder storms. The persistent, steady melting of the snow, no matter of what magnitude the snowfalls might be, would give us those regular or almost regular and light bands which we see in the banks of the Molyneux River, my lowest point of observation, and in the photograph which I show of the celebrated Mount Burster Claim, in the Kyeburn Ranges, some 4,000ft. above the level of the sea, which forms my highest point of observation. The deposits at the Blue Spur, Tuapeka, and other large sluicing-claims at lower elevations, tell the same story. The consideration of this subject is necessarily very absorbing to us as dwellers in this land of golden deposits. It indicates and points to the evidence of old channels of rivers, the objects of search to the miner and of possession to the speculator and capitalist; and it will not be denied that wherever the bed-rock in the Silurian formation has been reached large deposits of the precious metal have been found, as at Gabriel's Gully, Tuapeka, Butcher, and Conroy Gullies, adjoining the Manuherikia River, in the Molyneux Valley. Occasionally, also, rich deposits have been found when sinking in the terrace-formation, as at Ross Flat, on the west coast, and in the Cardrona Valley. These two latter may be pictured to our minds by considering the river-features of to-day—say, for instance, in the lower part of the Shag Valley, where the Shag River

land was once grand kauri forest: this is proved by the quantity of kauri-gum found on it. It has been worked as a gumfield—sometimes as many as two hundred men digging on it at one time—for the last thirty years (so I have been told by old residents), and yet it still yields a good quantity.

The cliffs on the coast show the same drift-sand nature down to sea-level. They also show that many great changes have taken place, and that the late kauri forest was not the first, for in the cliffs are several beds of good lignite, divided from each other by thick beds of drift-sand. This lignite contains many kauri-trees and fossil gum (ambrit).

The higher hills all have remains of old pas on the tops, and you can learn the history of them from the Maoris; but since my sons have had the place the remains of a very large old pa have come to light, of which the oldest natives say they have never heard. There are indications that the whole has been covered with forest, though not kauri, for kauri does not appear to have grown on the present coast-hills since the days of that pa.

When I bought the property this part was covered with a dense growth of fern, tutu, and scrub. This was burnt off, exposing the surface to the west winds, which removed the surface vegetable soil, then the sand, thus exposing bit by bit the ground-plan of a pa. It is on a large flat, and the process of uncovering is still going on. After a heavy gale my sons often find stone axes and pieces of stone, a kind of flint; but I have not seen any remains of wooden articles.

At one place, known as Mount Wesley (an old Wesleyan mission-station), the sandstone hills reach from the coast to the bank of the Wairoa, and one seam of the lignite crops out and forms a small reef in the river near the bank.

One strange feature of the country is the presence of a layer of blue clay or mud in a liquid state at varying depths. This mud was first found by my son in sinking a hole for a strainer-post. He hit the seam, and it ran over the top of the hole; and, though that is some nine years ago, it still runs at times, and has formed a quagmire about the place in which he has had many sheep smothered till he fenced it round. Recently a country road was cut through the hill at Mount Wesley. As the work proceeded one of my sons told the contractor that he was getting very near this mud, and cautioned him to alter his line slightly. The contractor laughed, and asked where mud was to come from on a hill; but a few more strokes of the pick hit the seam, and out flowed the mud, and the place had to be sheet-piled, and that only partly stopped the outflow. It was running along the side of the road when I was there a few weeks since. This mud or clay is just like what the early Wellington settlers used to call earthquake

enabled him to give a remarkably good account of some of its general features, and especially of its wonderful development of geysers and hot springs. He was, however, unable to ascend any of the great volcanic cones in the district, and he states that, although he gazed longingly at the massive outlines of Tongariro and Ruapehu, far to the south of the limit reached by him, neither time nor opportunity offered itself. Moreover, the Maoris had declared the mountain tapu, and would have strenuously opposed any projected ascent.

For many years little was added to our knowledge of the geology of the district, and it was not until after the unlocked-for eruption of Tarawera had recalled attention to the subject in so startling and emphatic a manner that further contributions were published. Mr. Cussen, in a paper read before this Institute last year, gave a general description of Lake Taupo and the country to the west, whilst in the reports on the Tarawera eruption by Mr. Percy Smith and the writer respectively there will be found additional information concerning the Taupo volcanic zone and the cones to the south. Mr. Park and Mr. L. Cussen have also published accounts of the ascent of Ruapehu.

Nevertheless the detailed description of the geology of the great cones to the south of the lake has not yet been given, and there is many a problem connected with the geology of the district which has scarcely been attacked. The present contribution to the subject is founded on observations made during various visits to the Taupo district, more particularly in January, 1888, when the writer passed a few days encamped at the foot of Tongariro. His time was chiefly spent in the examination of Tongariro; and a contemplated visit to Ruapehu was delayed by other work undertaken for the Government. He trusts, however, to have an early opportunity of making a more extensive examination of other parts of this locality.

Perhaps the greatest interest centres round the Ruapehu–Tongariro chain of volcanic mountains, for we have here no fewer than three cones—viz., Ruapehu, Ngauruhoe, and Tongariro—which have shown signs of greater or less volcanic activity within recent years. This chain (see Plate XXVI.), which has a length of fifteen or sixteen miles in a direction 26° east of north, rises up from the centre of a plateau nearly 2,000ft. above the sea-level. The plateau is bounded on the east by the Kaimanawa Range, composed of the ancient Maitai (Carboniferous) slates and sandstones, rising to a height of 5,225ft. in the Umukarikari Mountain. The Ruapehu–Tongariro line is nearly parallel to this range at a distance of some ten miles. To the west the

plateau is bounded by a range of mountains which passes northwards into the main range west of Taupo Lake. On the north the plateau is separated from Lake Taupo by the volcanic mountains Pihanga and Kakaramea (4,266ft.) and the ridge of volcanic rock which connects them. The Waikato River (called in this part of its course by the natives the Tongariro) rises in Ruapehu and flows northwards towards Lake Taupo, receiving many tributaries from the eastern side of the Ruapehu–Tongariro chain and from the western slopes of the Kaimanawa Range, and passes to the east of Pihanga as a broad, shallow, swiftly-flowing river. It enters Lake Taupo at the southern end, about two miles from Tokaanu, and has formed a very considerable delta, composed of the débris of volcanic rock from the western sides of the various cones, and of the slate found in the Kaimanawas. These two materials, of such different origin, are present in approximately equal proportions.

Ruapehu is the highest of the great volcanic cones, rising to 8,878ft. Many observers seem to have suspected that the vapour hanging about the summit on certain occasions, even in fine dry weather, was due to volcanic energy in the mountain; but it was not till April, 1886, when Mr. Cussen ascended the mountain, that the matter was placed beyond doubt.^* He found a lake of warm and steaming water occupying a basin about 300ft. below the two chief peaks of the mountain. No steam was rising from the mountain during my visit to the district in 1888; but I was informed that it had been seen a few weeks earlier.

The summits of Ruapehu and Ngauruhoe are distant from one another a little more than eight miles, but they are connected by a ridge of volcanic rock, on top of which lie two lakes known by the name of Nga Puna-a-tama. These lakes appear to lie in craters which mark the sites of former centres of activity along the volcanic line.

Tongariro lies close to and abutting on the north-east side of Ngauruhoe, and the latter mountain is often miscalled Tongariro. The two mountains, though so close together, are sufficiently distinct in form and position to call for separate recognition.

Ngauruhoe.—Ngauruhoe is considerably higher than Tongariro. It forms a beautifully regular steep-sided cone, which rises to the height of 7,481ft. The height is greatest to the east, so that viewed from the north the mountain has an obliquely-truncated appearance. From the crater on the top steam constantly issues in considerable volumes, and, driven

before the wind, forms a long train to leeward. To the north the crater-margin is partly broken down, and the surface of the ground here is rotten and treacherous from the action of the acid vapours. The hydrochloric acid in the vapours reacting on the iron oxides in the scoriæ forms considerable quantities of perchloride, of iron, which stains the ground brilliant shades of yellow and orange, distinctly visible even from the top of Tongariro.

The sides of the cone are for the most part smooth and regular, and are formed of scoriæ and fine ashes, but here and there rugged projecting rocks mark the course of lava-streams. One of these, which descends as far as the south crater on Tongariro, ends there in a steep front of lava, with black scoriaceous surface, about 30ft. in height. This stream is said to be that which flowed from the crater during the eruption of Ngauruhoe in 1869.

It has been reported that Ngauruhoe has shown great signs of activity recently. I am indebted to Mr. Howard Jackson, the engineer in charge of the road-makers near Tongariro, for notes and sketches (see Plate XXVII.) bearing on the subject. Mr. Jackson has been in the district almost continuously for more than twelve months, within full view of the mountain. He states that on the whole the mountain has shown, if anything, rather less activity than usual, but that during bad weather which occurred in April or May, 1888, a gap was formed by the breaking-in of a portion of the crater-wall to the east. As seen either from the east or west, there is now a deep V-shaped notch which must have the depth of about 200ft. (see Plate XXVII., figs. 5 and 6). A comparison of the present outline of the cone with the drawings made by Hochstetter in April, 1859 (figs. 1 and 2) shows that a large amount of change has taken place since that date.

Although Ngauruhoe rises so high above the sea-level, the snow does not lodge long on the cone: the ground in many places is warm, and the internal heat passing slowly outwards, together with the steam rising from the crater, is sufficient to thaw the snow. The steam which rises so constantly from Ngauruhoe comes chiefly from a smaller, deeper crater, with dark and steep sides, lying within the circle of the principal one. From this crater ashes and fragments of scoriæ are frequently ejected.

Tongariro.—Tongariro, the third of the great mountains, is, strictly speaking, composed of a number of distinct cones built up around so many separate points of eruption. These cones, however, are so close together that the mountain forms at its base a single mass. Viewed from a distance the mountain has a broad, flat-topped appearance, but as it is

approached the separate cones of which it is formed at the top become more distinct. (See Plate XXVIII.) The lower slopes of the mountain are composed of lava-streams, which stretch as far as Rotoaira, the lake to the north; indeed, the formation of the lake appears to be due to the blocking of the drainage-channel by a lava-stream. These lower slopes are covered with tussock-grass, which affords a certain amount of support to animal life, so that the slopes of the mountain have been employed as a sheep-run. On the north side there is a large area of forest. Amongst the tussock-grass small herbaceous plants with bright-coloured blossoms grow in far greater abundance than is usually seen in New Zealand except in alpine districts. The summit of the mountain is all but devoid of vegetation.

That portion of Tongariro which lies to the east is often termed by the natives Te Mari, whilst the part to the west is Tongariro proper. The top of the mountain is marked by seven large craters, as well as some smaller ones. The distribution of these will be best gathered from the accompanying sketch-map (see Plate XXIX.), which will, I believe, be found sufficiently accurate for our present purposes.

The ascent of the mountain is most easily accomplished by way of Ketetahi, a hollow at the height of 4,900ft. on the side of the cone which forms the north-west angle of Tongariro. Ketetahi is not, properly speaking, a crater, though explosions of steam seem to have assisted in the excavation of the hollow: it resembles rather the enlarged head of a gully. There are many hot springs and a powerful escape of steam here, whilst the overflow of the water forms a warm stream. The volume of steam rising from Ketetahi is usually very considerable—so copious, indeed, as to render the spot visible for a distance of fifty miles.

Two other places on Tongariro are marked by the escape of steam, which betrays the volcanic forces dormant within the mountain. One of these is on the northern slope of Te Mari, the other is in the Red Crater; but neither shows so much activity as Ketetahi. Above Ketetahi the slope of the cone becomes steeper. It is formed of lava having a comparatively smooth surface of step-like formation, which greatly facilitates the ascent.

On reaching the summit of the cone a remarkable sight presents itself. The top is formed by a circular area half a mile in diameter, which at first strikes one as being perfectly flat. Closer examination, however, shows minor undulations, the surface of the wind-swept ground being strewn with fine sand-like volcanic ashes and lapilli. To the north, and, again, on the opposite side, towards the south, a cliff of lava rising perhaps to 100ft. above the crater-bottom forms the boundary

of the area, whilst elsewhere around the margin the ground dips down abruptly to the steep outer slope of the cone (see Plate XXX). The two lengths of cliff and a few other rocks in the same circle evidently mark the former rim of a crater, which at a subsequent period was filled up by lava, which overflowed the brim and formed streams on the rocky sides of the cone. From its position we may distinguish this filled-up crater as the North Crater of Tongariro. On the west side, and just within its margin, it contains a smaller funnel-like crater of considerable depth. The cliff to the south is chiefly formed of thick horizontal beds of dark lava. At the western angle of the cliff the smooth and slightly-weathered surfaces of the joints in the lava show a remarkable streaky structure, visible from a great distance. This flow-structure, which bears testimony to the unequal movements in the lava at the time of its consolidation, is due to the irregular alternation of a light- and dark-grey material in the ground-mass of the lava. Near this spot the surface of the ground is covered with a layer of an exceedingly light pumice of acid composition, differing greatly from the other rocks found on the mountain. The largest of the fragments was 14in. in its longest diameter. Reference to this and other rocks on Tongariro will be found further on.

Between this North Crater and the rest of the Tongariro system is a dip of 200ft. or 300ft., by which it is marked off from the rest of the mountain-top. To the south, and stretching as far as the slope of Ngauruhoe, is another cone, marked by a very large crater, over half a mile in length. This crater, which we may suitably distinguish as the South Crater, is of a much elongated form, and it is worthy of note that its long axis coincides in direction with the Tongariro–Ruapehu line.

Its walls are very steep, and in many places precipitous. They are highest at the end towards the North Crater, and gradually diminish in height in the direction of Ngauruhoe. The highest part of the crater-wall, which is also the highest point on Tongariro, lies on the western side, and is about 6,450ft. above the sea-level. The crater-flow lies over 800ft. below this point. At times the bottom of the crater must be covered in part by a shallow lake, which discharges at the end towards Ngauruhoe. The water will pass down the watercourse between the latter mountain and Tongariro, and form the beginning of the Mangatepopo Stream, a tributary of the Wanganui River.

Travelling along the ridge which forms the eastern boundary of the South Crater, we pass two large craters on the right. The first of these has high precipitous sides towards the west, whilst to the east its wall is wanting,

and the eye stretches over vast fields of rugged hummocky lava.

The second, or Red Crater, lies further to the north, and is interesting as showing the signs of recent activity. The crater has very steep sides, so that from the west at least it is not possible to descend into it. The upper part of the crater is formed by a great thickness of beds of dark blood-red scoriæ having an extremely close resemblance to the layers of scoriæ of the Tarawera eruption which lie piled up on the borders of the fissure on the Tarawera Mountain. It is said that steam can be frequently seen issuing from this crater; but none was visible on the occasion of my visit. Around the margin of this crater blocks of a dark heavy lava, having the appearance of a basalt, and more basic than the usual lavas of the mountain, are to be found. Across the floor of the crater is a small lava-stream.

To the north of the Red Crater, on the part of the mountain called Te Mari, is an old crater of considerable size. Lying to the east of this, and separated by a comparatively low ridge of rock, is another crater, containing a lake of the most beautiful blue water (see Plate XXXI.); whilst on a ridge between this and the Red Crater are two much smaller lakelets, one of which from its colour has been called Rotopounamu (Greenstone Lake).

On the north-eastern slope of Te Mari is yet another crater of considerable size, and close to this, as already mentioned, there is a large but intermittent escape of steam.

Lake Taupo.—It is not my intention to enter here into a detailed description of Lake Taupo and the surrounding country, but merely to mention such points as we shall have occasion to refer to hereafter or as have not been previously described. The lake has an area of nearly 242 square miles; it is 24⅞ miles in length and 16½ miles in extreme width, and has a shape which has a general resemblance to that of the continent of Africa. In many places the lake is bounded by steep cliffs of lava and associated tuffs. That the lake formerly stood at a higher level is clearly shown by the terraces around it, which are continued up some of the small valleys leading into the lake. One terrace stands at a height of 100ft. above the present water-level of the lake. The accompanying plate (Plate XXXII.) shows this terrace at the south end of the lake, about three miles from Tokaanu, looking in a northerly direction. Another well-marked terrace lies at the height of 300ft. to 400ft. above the lake.

The lavas at the north, east, and part of the western sides are rhyolites; at the south end they are chiefly augite-andesites. The pumice-deposits which form so remarkable a feature of the Taupo district are found to a greater or less

extent all round the lake; they are thickest, however, near the northern end, reaching the thickness of 300ft. in one of the cliffs. Throughout the district, indeed, the pumice is widely spread over the surface of the ground, especially to the east, north-east, and north of the lake. It is found even on the summits of the highest mountains—here, however, merely as a sprinkling, whilst at the bases of the hills and in the valleys it may reach the depth of hundreds of feet. The manner in which the river-valleys have been filled up with pumice, out of which the water has excavated terraces, is sufficient evidence of the influence of running water in distributing the pumice. There are, however, many facts which show that much of the pumice has travelled through the air and fallen in showers in its present position.

Popular belief ascribes this pumice to the great volcanic mountains Ruapehu, Ngauruhoe, and Tongariro, which lie to the south of the lake, the showers of pumice being supposed to have been brought by the prevailing south-west winds. Any one who will examine the distribution of the ash from the Tarawera eruption^* will see that the explanation has a primâ facie probability, for in that case the ash was spread out in just such a manner. But the examination of the neighbourhood of Tongariro shows that such an explanation is not applicable to the distribution of the pumice in the Taupo district. The pumice is less abundant in the neighbourhood of the great mountains than elsewhere in the district, and, as will be shown further on, the rocks of Tongariro belong to a different group. The pumice around Lake Taupo contains considerable quantities of rhyolite - fragments other than pumice, especially of the perfectly-laminated variety which has been termed lithoidite. Near Ouaha, on the east side of the lake, I found angular blocks of lithoidite 3ft. and more in diameter, and weighing two tons or more, imbedded in the pumice-deposits. It is obvious that blocks of this size cannot have travelled any great distance, whether by the agency of water or the force of volcanic explosions, but must have been derived from some source near at hand. The only localities near Taupo that I am acquainted with where this variety of rock is found in sitû in lava-streams are at Motutaiko, the island in the lake, and Hamaria, three or four miles distant, on the shores of the lake. We might perhaps not unnaturally look to Tauhara, the volcanic cone at the north end of the lake, as a source of part of the pumice. This mountain has the height of 3,603ft., and the country at its base on both

sides of the Waikato River is remarkable for its vast number of hot geysers, &c. The mountain has a large crater on top (Hochstetter stated that there was no crater), and its upper part is thickly covered with forest. I found on top of Tauhara a sprinkling of pumice, with small fragments of lithoidite quite different from the rock of which the mountain consists. The lavas, as far as I observed, are all of acid composition, but contain a rather large amount of hornblende, a mineral not found, so far as I have seen, in the pumice-deposits.

Hochstetter supposed that the formation of Lake Taupo was due to subsidence of its area, a supposition which is strengthened by the abrupt, precipitous character of part of its shores and the fairly uniform depth of its waters. A more popular theory supposes Lake Taupo to have been an immense crater; but evidence of this is wanting, though it is quite conceivable that the sunken area was marked by vents from which perhaps a portion of the pumice which covers the district was derived.

The Waikato leaves Lake Taupo at the north-east end of the lake, and for the first part of its course flows to the north-east in a gorge through rhyolitic tuffs. Three miles from the lake its course is broken by the Huka Rapids and Fall. The tuffs here are locally hardened by the deposit of a siliceous cement from the hot springs, which have attained a considerable development at one time, and are indeed still represented by one or two warm streams close to and above the rapids. The river on reaching the harder rock becomes suddenly narrowed to less than a quarter of its usual breadth, and, confined to a narrow channel with vertical sides and sloping bottom, rushes through it with an arrowy swiftness which the eye can scarcely follow, until at length it plunges downwards some 30ft. into a wide basin of water eaten out of softer rocks. Some of the finer pumiceous sands here contain such an abundant siliceous cement of siliceous sinter that to the naked eye they have the half-glassy appearance of a pitchstone, and have, indeed, been described as lavas.

A few miles further on, however, the Waikato crosses a series of lava-streams, and the harder rocks have led to the formation of the beautiful rapids known as the Aratiatia Falls. The lavas are rhyolites, chiefly of a glassy character, spherulitic obsidians being well developed.

Volcanic Fissures in the Taupo Zone.—We have already seen that the Tongariro–Ruapehu group of volcanoes are arranged in a straight line, which doubtless represents a fissure in the earth's crust by which the molten rocks have forced their way to the surface. It affords, indeed, a remarkable instance of a number of volcanic vents arranged close together on the same fissure. We have the huge mass

of Ruapehu at one end, then the two crater-lakes of Nga Puna-a-tama, the lofty active cone of Ngauruhoe, and then the direct line is continued by the South and North Craters on Tongariro.

If, with a slight deviation in direction, the line be continued to White Island, we find that it passes through a large number of points remarkable for their volcanic activity, including Tarawera and Rotomahana. This line may therefore be justly looked upon as the main line of volcanic activity in the Taupo volcanic zone.

Nor is this the only instance of great fissures connected with the volcanic activity of the district. In the northern part of the Taupo zone we have two lines marked by hot springs as well as by dislocation of the rocks. These lines are parallel to the main line, and probably correspond to great fissures in the rocks. The first of these lines, seven miles from the main line, stretches from Orakeikorako along the east face of the Paeroa Range to Rotoehu, a distance of thirty-seven miles. The second line is eight miles further to the west, and stretches from the hot springs on the Waipapa Creek, near the Waikato, through Rotorua to Rotoiti.

We may reasonably ask whether these lines of fissure are represented further to the south. If they are produced in that direction they will be found to coincide generally with the lie of the shores of Lake Taupo. The main line will correspond with the eastern shores; whilst the Orakeikorako line will correspond with the western shore of the lake from Waihi to the bold and precipitous headland of Karangahape—i.e., south of Western Bay; and the Rotorua line will correspond with the western shores of the broad arm of the lake known as Western Bay.

It will be noticed, however, that the coincidence is not exact, the lines showing a tendency to converge as we approach the south, the point of convergence being Ruapehu. There can be no doubt that Ruapehu marks the position of an important centre with reference to the broader structural features of the North Island. It is here, or near here, that the line of elevation marked by the northern peninsula joins the main axis or backbone of both islands. The line of the western coast of the peninsula north of Auckland, if produced, will be found to pass approximately through Ruapehu. In other words, the structural axes and dislocations of the country radiate from near Ruapehu, and the manifestation of volcanic forces here is determined by its position with reference to the great flexures of the earth's crust.

The examination of these radiating lines cannot fail to remind the geological reader of the system of cracks obtained by Daubrée during experiments on the fractures produced in

homogeneous substances, such as ice, by torsion.^* Such systems of fractures may also be readily obtained in glass. Daubrée obtained systems of fractures crossing one another at angles approaching a right angle. In each system some of the fractures were arranged in a radiating or fan-shaped manner, others were parallel to each other. Great caution, of course, is needful in applying such results to the explanation of natural dislocations, for it is uncertain how far we are justified in supposing the earth's crust would behave as a homogeneous mass, and the conditions of the experiment are no doubt very different. Still, the resemblance of the arrangement of these natural dislocations to that of the artificial fractures is sufficiently close to lend interest to the comparison.

Many instances of transverse dislocations might be cited in the Taupo zone. The line of volcanic mountains at the south end of Lake Taupo may be due to such a fracture. We have here the two mountains Kakaramea (4,266ft.) and Pihanga, of about the same height. They are connected by a high ridge of volcanic rock, and the long axis of the group lies at right angles to the line of the Ruapehu–Tongariro fissure. Pihanga has a crater showing to the north, and Kakaramea is said to have traces of a crater. The rocks of which they are composed are generally similar to those of Tongariro. Where the slopes of these mountains come down to the south shore of Lake Taupo we find the hot springs and geysers of Tokaanu, as well as various springs at intervals as far as Waihi.

Rocks of Tongariro.—Specimens of rocks from Ngauruhoe and Ruapehu were collected by Mr. Cussen in 1887, and were described by me in the “Transactions” of the Institute.^† Since then I have had the opportunity of making very extensive collections of rocks on Tongariro and in its neighbourhood, and am able to add to what was then written. I am indebted also to the great kindness of Mr. J. A. Pond, Colonial Analyst, for a valuable and extensive series of analyses of rocks from Tongariro, Ngauruhoe, and Lake Taupo. These furnish an important and welcome supplement to the results obtained by microscopical examination.

Hochstetter has stated that all the rocks collected by him in the Taupo volcanic zone belonged to the family of acid volcanic rocks known as rhyolites. In the paper referred to it was shown that the intermediate (or slightly basic) group of lavas known as the augite-andesites were largely represented in the district. This result is amply confirmed by Mr. Pond's

analyses. My own collections show that the typical rocks of Tongariro are augite-andesites, though more basic rocks, which may be regarded as members of the basalt group, are also represented. Perhaps the commonest variety of these augite-andesites is one which is found, amongst other places, on the slope of the North Crater of Tongariro, where it forms the lava-streams above Papakai. Similar lavas descend as far as the shores of Rotoaira. The rock is a porphyritic one, of medium grain and dark colour, showing when quite fresh a slight resinous lustre. The porphyritic crystals are numerous, but none of them reach a length of over 3mm., and they are usually much smaller. Examination with the microscope shows that the porphyritic crystals consist of felspar and augite in about equal proportions and in well-formed crystals; there are a few smaller magnetites in irregular crystals. The felspars are almost all striated, and many of them are crowded with inclusions of glass, which is sometimes brownish and pure, at other times is colourless, but containing globulites and dark granules. The felspars also contain inclusions of augite and apatite. The augites are in eight-sided prisms; in thin section they are yellowish and only feebly pleochroic, the range of tints being from greenish-yellow to brownish-yellow. A few of the largest augites are completely honeycombed by groundmass. The groundmass is hyalopilitic—i.e., it consists of a felt of crystallites united by rather abundant colourless glass. It contains a considerable number of black granules of magnetite. The crystallites include great numbers of long, slender, non-polarising longulites, and very few of these incipient forms are sufficiently developed to polarise. Olivine is altogether wanting in the rock. The augite and felspar not unfrequently occur in nests composed of great numbers of crystals, which only show their proper form on the exterior of the groups. The analysis of this rock is shown as No. 1 in the following table. Its specific gravity is 2·76:—

[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]

Nos. 1–4 are from Tongariro: No. 1, an augite-andesite from the lava-stream wich reaches Rotoaira; No. 2, ditto from Otouku; No. 3,

ditto from Red Crater; No. 4, ash on slope of Tongariro; No. 5, augite-andesite, the lava of 1869, Ngauruhoe; No. 6, pumice from North Crater, Tongariro; No. 7, rhyolite lava from Motutaiko; No. 8, lithoidite from Hamaria, Lake Taupo.

Other varieties of augite-andesite from Tongariro differ chiefly in the degree of devitrification of the glass, the porphyritic crystals being essentially the same. Specimens may be obtained in which the groundmass is quite free from crystallites, and consists of a pure glass of a rich brown colour. That this was the original condition of the ground-mass in the other varieties may be seen from the inclusions of brown glass in some of their larger felspars. Here we must include specimens of brownish pumice, which contains augite and plagioclase in crystals and groups of crystals—evidently only a similar rock distended with very numerous minute vapour-cavities.

On the side of Ngauruhoe which slopes down to the South Crater on Tongariro, is a lava-stream which is said to have flowed from Ngauruhoe in 1869. This stream ends in an irregular front just where the slope of the cone joins the flat bottom of the crater on Tongariro. The lava is much fissured, and the smooth surfaces of the blocks have a strong glassy lustre. This lava is essentially like those on Tongariro, except that the groundmass is rather more glassy, and is perhaps richer in iron-oxides. The proportion of silica, however (see analysis No. 5), is rather lower, being only 57·0. Its specific gravity is 2·82.

Amongst other lavas of Tongariro may be mentioned that which forms the blocks of lava at the bighest point of Tongariro. This contains a few crystals of olivine. The same mineral occurs in crystals visible to the naked eye in the lava which reaches Otouku. This rock is shown by its analysis (see No. 2) to differ but slightly in chemical composition from the commoner type of Tongariro lava. Its structure, however, is very distinct. The porphyritic crystals are not numerous, but include plagioclase, augite, and olivine. The groundmass is almost entirely crystalline, and shows a pronounced fluidal structure. It consists of small augite prisms and minute laths of felspar, with scanty magnetite granules. In parts of the rock a little glass may be traced; in others it appears holocrystalline. The fluidal structure is due partly to the parallel grouping of the felspar laths, but more especially to the arrangement of the augite and felspar in such a way that along certain lines the minute augite crystals largely predominate, along others the felspar laths. The specific gravity is 2·83, being doubtless a little higher on account of the crystalline character of the groundmass.

A rock which occurs in blocks around the Red Crater is

much more basic than any of the preceding rocks. It is heavy and black, with all the appearance of a basalt, and shows microscopic olivine. It contains, however, felspar and augite crystals like the porphyritic crystals in the augite andesites previously described. They are not very abundant, and to them are added olivine in numerous crystals, and felspar laths. The groundmass is in the main crystallitic, but shows far more crystalline particles between crossed nicols, and glass is scarcely visible. The rock thus shows a relationship to the augite andesites, but at the same time approximates to the basalts. Another variety collected by Mr. Cussen contains chiefly olivine among the larger crystals, though a few smaller augites are present. The groundmass is partly crystallitic, but contains very numerous felspar laths.

The analysis of the former variety by Mr. Pond shows (see No. 3) that it contains 52·1 per cent. of silica—an amount considerably higher than that usually present in rocks recognised as augite-andesites. Its specific gravity is 2·94, which also indicates a rock more basic than ordinary augite-andesites. The magnesia and lime are also present in much higher proportion than in the other rocks of Tongariro. Rosenbusch, in his last edition,^* states that the augite-andesites seldom contain less than 56 per cent. of silica, whilst some basalts attain the same percentage. Teall quotes twenty-three analyses of porphyrites and andesites as varying between 66·75 and 54·73 per cent, of silica, whilst the same number of basalts showed percentages of silica varying between 53·73 and 42·65.^† Under the circumstances, we shall probably be justified in terming the rock a basalt, though we must admit that it is closely related to the augite-andesites. The system of classification of rocks is necessarily more or less arbitrary, and the present rock is one which lies near the line of division between the augite-andesites and the basalts.

Pumice on Tongariro.—We have referred above to the popular idea that the great quantities of pumice around Lake Taupo are derived from Tongariro and Ruapehu, and have stated that the examination of the country to the south of Lake Taupo lends little support to any such theory. Pumice is indeed found on Tongariro, but in comparatively small quantity. A small amount of pumice of an acid character, containing 75·25 per cent. of silica (see analysis No. 6), was found in the North Crater of Tongariro, and one or two small fragments of rhyolites were found elsewhere on the mountain-top. But with these exceptions all the rocks high up on the mountain were of a more basic character. On the lower