Art. XXXIII.—Rotomahana and District revisited Twenty-three Years after the Eruption.
[Read before the Hawke's Bay Philosophical Institute, 24th June, 1910.]
The Tarawera eruption took place on the 10th June, 1886. In the months of February and March following I visited the volcanic area extending from Ruapehu to Mount Tarawera. My purpose was to study volcanic phenomena as presented by this almost unique extent of country, known generally as the Taupo volcanic zone. The distance in a straight line is a little over a hundred miles. Within this extent of country all aspects of volcanic phenomena occur, from the active volcano, as Ngauruhoe and Tongariro, to the slowly dying ngawha and puia as seen at places like Tokaanu, south of Lake Taupo, and Rotokawa, a few miles to the north of it. Twenty-three years have gone by since that visit took place, and in company with A. J. Morton, Inspector of Schools, Westland, I have purposely made another visit to the northern portion of the district, or more particularly that portion which was directly affected by the eruption in 1886. Twenty-three years is a fair measure of time in the life of an
individual, and it provides a kind of standard in estimating the physical changes of a district when they are unaffected by artificial agencies.
The past, as read in the rocks about us, goes a long way back, and our ideas of time are so limited that none of us can measure a geological period without some standard of time in relation to moving events as they affect the human race. We know literally nothing as to the incoming of special formations of rocks, or the time that it took in their making; nor do we know whether fifty or a thousand centuries have elapsed since the present forms of organic life came into being. In nature's ever-active workshop changes are going on, and how small is the period which our modern fauna and flora represent of the evolutionary process that has ever been in operation, which embraces the whole gamut of past life down and back to the time when life first became possible on a cooling earth. It was some such thoughts as these that led me to renew my acquaintance with a district that had formed the subject of scientific dissertations, that had been the scene of stupendous changes in mountain, lake, and valley, and which in a brief six hours had produced devastation over a vast district estimated in thousands of square miles, and but for the isolation of the area would have resulted in the loss of many lives. Every living plant and animal within some miles of the centre of volcanic disturbance was destroyed, and there was also loss of human lives.
It is not necessary for me to refer at length to the extent of the destruction caused by the Tarawera eruption. Details were published throughout the Dominion and are still available to inquiriers, and scientific accounts have been issued under the authority of the Government. Among these may be mentioned the separate accounts by the late Sir James Hector, Director of the Geological Survey; by the late Captain Hutton, F.G.S., F.R.S.; by Professor Thomas, M.A., F.G.S., of University College, Auckland; and last but not least by Mr. Percy Smith, F.R.G.S., late Surveyor-General. The accounts given by these scientists provde valuable literature dealing with certain aspects of vulcanism as obtained immediately following the outbursts at Tarawera.
As already remarked, the scene of the eruption was visited by me in February and March, 1887. My guide was the late Mr. J. C. Blythe, who had passed through the ordeal of the eruption at Wairoa Settlement, on the west side of Lake Tarawera, when the place was utterly destroyed. Mr. Blythe was Government officer in charge of the road-construction, and he knew intimately the whole country extending from Galatea to Taupo and from Taupo to Rotorua. His knowledge of the district was of much value to the authorities immediately following the eruption; but, although he lived to help many, and to tell others subsequently of his never-to-be-forgotten experiences on the eventful morning of the 10th June, his nerves were so shattered that he became a wreck of his former self, and, although as an old friend I tried to cheer him at my home in Napier, it was only of temporary benefit, for on his return to Rotorua district he lived for only a comparatively short time. Mr. Blythe was my guide and companion from Rotorua over the whole of the country that had been immediately affected by the eruption. We visited the rift in the Tarawera Mountain, the site of Wairoa, Rotomahana crater-basin, the earthquake flats towards Pareheru and the Tikitapu; the creater-valley forming a continuation of the rift, and which subsequently became so celebrated or notorious by the break-out at Waimangu; the mountains known as Kakaramea and Maungaogaonga, at the head of the Waiotapu Valley; and finally made our way through
the latter valley, and christened the place known as the Primrose Terrace. At that time the Waiotapu Valley had hardly been visited by Europeans, and but for our guide the visit would have been a dangerous if not a foolhardy undertaking.
One well remembers the scene of desolation that appeared after getting over the hills from Whakarewarewa, near Rotorua. Looking towards the Tikitapu Bush and the lake and mountain known as Tarawera, the country presented a dull-grey appearance, and not a truce of grass or fern or bush was to be seen. A valley on the road to Tikitapu had been rent in twain by an earthquake, which had produced a gulch from 30ft. to 40ft. in width and 50ft. or more in depth. This extended for a long distance, and divided into three cracks or prongs to the eastward, where the rift shallowed. It seemed as if a sudden uplift had taken place, and that a wedge-shaped piece had been suddenly broken from the valley-level and had fallen and wedged itself as the upward strain was lessened and the surface pressures gave their usual stress upon the underlying rocks. The sides of the crack were vertical, as if sheared with an instrument, although nothing but pumice appeared in the sides throughout the entire length of the depression. Further in the direction of Te Wairoa Settlement the site of the Tikitapu Bush was reached, but everything had been destroyed by the falling débris and the battering of the trees by the mud that was flung from Rotomahana. The Tikitapu Lake and its adjoining one, Rotokakahi, which at present are known as the Blue Lake and the Green Lake respectively, presented a desolate appearance, the sides being mud-clad, and large furrows showed themselves from the hillsides, where the rains had carried material into the lakes during wet weather. The small stream from the Green Lake had been dammed back by the mud, and the entire country presented not a trace of either animal or vegetable life.
The Te Wairoa Settlement had been the residence of a number of Natives. There was a church, a Native school, and an hotel, the latter being specially built for the convenience of tourists to Rotomahana. Everything had been destroyed; not a house was left intact, and the majority had been overwhelmed. A Native whare belonging to Guide Sophia had stood, being protected by its position, and this place formed a “whare of refuge” for a number of persons who sought its friendly protection. The church and school were destroyed, and Mr. Haszard, the schoolmaster, with a number of others, lost his life. From the roof of the church one could see where the services had been held, and “Church Services” were to be seen here and there besprinkled with mud, but all, or nearly all, those who had formerly worshipped had lost their lives. The picture remains in my memory, and it is set down here twenty-three years afterwards to show the impression made upon me, for I have not previously written on the subject.
We continued our journey towards Rotomahana and the great rift, and from the hill named Te Hape-o-toroa, overlooking what had once been the hot lake Rotomahana, containing an area of about 200 acres, and abounding with terraces, puias, ngawhas, and geysers, there appeared an immense yawning abyss, from which steam arose as from hundreds of throats that at times sent out dismal sounds and hissings as awesome as from Dante's inferno. The sight cannot be described, and one could only wonder as to the forces that in the course of a few hours produced such an enormous crater in place of a hot lake and its inimitable terraces. Great steam-clouds rose from the abyss, and from the rift in the mountain, and
from several crateral lakes near by. Sometimes the southern slope of the Tarawera chasm or the mountain could be seen. Here the volcanic forces had rent asunder a whole mountain-side before reaching Rotomahana, where the volcanic phenomena were quite different from those on the mountains. Stones and cinders, ashes and sand, with an abundance of the finest powdery steel-grey dust, were hurled from the mountains, but mud alone, of a bluish-grey colour, appears to have been sent from the Rotomahana Crater. We followed the rift towards Okaro Lake, and saw the various crater-shafts that had been made in various places. Some of them had thrown out enormous stones, tons in weight. These had fallen into the mud-covered area, and had made depressions that presented a curious saucer-like appearance over the country. Some of the craters were mere circular shafts of great depth, but we were unable to form an estimate of the depth, as the stones rolled into them sent back no thud or sound of any kind. To me the rift had the appearance of a great upheaval of country where a line of hills had been rent or torn asunder and thrown apart, leaving the rift-valley between them.
The destructive effects of the eruption were not felt to the southward beyond the ridge that separates the drainage of the Rotomahana area from the Waiotapu Valley, for, although careful observation was made, the only trace of activity having occurred in the valley was the discovery of small globules of black sulphur near to the Primrose Terrace, and within a short distance of the great mud volcano near a terrace formation.
Nature heals very rapidly the wounds she makes. Rearrangement and renewal are always in progress, and no sooner has one aspect of the earth's crust played an important part than new energies begin to manifest themselves, so that the old is quickly replaced by the new.
Before, however, noting the changes that have taken place as noted by me, it may be of some value to future inquirers to set down here what was known by Europeans of Rotomahana and Tarawera up to the time of the eruption. In no record that has come under my notice is the Waiotapu Valley mentioned, and the first European to visit Rotomahana was the Rev. Mr. Chapman, a missionary. In the Missionary Record of June, 1838, it is reported that Mr. Thomas Chapman started from Paihia (Bay of Islands) for Rotorua on the 2nd February, 1835, with a Mr. Pilley, and that they reached the place on the 19th March. In August of the following year the missionary station at Rotorua was burnt, and Mr. Chapman went to Taupo, where, in May, 1841, he met Dieffenbach, the scientist sent out by the New Zealand Land Company. Dieffenbach had been to Tokaanu, and was travelling northward when he appears to have met Mr. Chapman, from whom he obtained information about Rotomahana. On the 1st June Dieffenbach reached Rotomahana, and he writes, “Towards evening [1st June] we reached the hills which surround on all sides Rotumahana. When we arrived on the crest of the hills the view which opened was one of the grandest I had ever beheld. Let the reader imagine a deep lake of blue colour surrounded by verdant hills, in the lake several islets, some showing the bare rock, others covered with shrubs, while on all of them steam issued from a hundred openings between the green foliage without impairing their freshness; on the opposite side a flight of broad steps of the colour of white marble with a rosy tint, and a cascade of boiling water falling over them into the lake. Some Natives came over in a canoe to fetch us over the lake to their settlement. Mr. Chapman was probably the first European they had ever seen, as this lake has not been
visited by any other that I am aware of. The Rotu-mahana is not more than a mile in circumference. We crossed from it in a canoe into the lake Tarawera. The stream connecting them is tepid, and of a temperature of 85°. It is appropriately called Kaiwaka (canoe-spoiler), as the canoe often touches the rocks of which the bottom is formed.”
In the “Tasmanian Journal of Science,” vol. 1, page 268, there is given an account of a journey by the late Rev. W. Colenso, F.R.S., taken in the North Island of New Zealand in 1841–42. Mr. Colenso reached late one night Lake Rangiwaka-aita, now known as Rerewhakiatu, which is situated about two miles to the east of Lake Rotomahana. He describes the former lake, and states that the country was overspread with many blocks of compact lava, many being vitrified on the surface. The ground rose gently from the lake on every side, which appeared to occupy a deep hollow, and “I could but venture to suppose that this might perhaps have been the crater of a volcano which in some bygone age inundated the whole country with showers of pumice and ashes. At an early hour the next morning we rose, feverish, stiff, and sore, to recommence our march. We soon came within sight of the place where the hot springs were situated [Rotomahana ?], from which the steam and sulphurous vapours ascended in dense white clouds. The air this morning was cool and bracing, and after travelling about an hour and a half we arrived at Tarawera Lake [Te Ariki?]. At this place were several small hot springs, which flowed out of the earth near the edge of the lake; the water of some was hotter than one could bear…. The Natives of the village informed me that at a spring on a hill a little distance away the water was quite hot enough for the purpose of cooking, for which they often used it. Sulphur, too, abounded there, and was often ‘thrown up’ out of the earth, from which the steam and smoke ever ascended [the White Terrace?].” This “steam and smoke” was, of course, from Rotomahana geysers and puia, and although Mr. Colenso started to visit the place while breakfast was getting ready, he gave up the quest, “his hunger,” as he said, “conquering curiosity”; and thus he missed, although less than three-quarters of a mile away, seeing, as the third European visiting the district, the inimitable terraces. It is strange that a missionary traveller like Mr. Colenso, who was so very observant, should have passed from the east to the north end of Rotomahana by way of the south and west and yet did not see the lake.
Hochstetter was the next traveller of note to visit Rotomahana. He spent three days in April, 1859, visiting every place of interest within the precincts of the lake, and made observations of great scientific value. The map of Rotomahana Lake by Hochstetter and Petermann, published in 1863 at Gotha by Justus Perthes, is the only map, as far as I can discover, that appeared in an official dress or under authority previous to the eruption. Of Rotomahana and the Terraces Hochstetter thus writes: “The Rotomahana is one of the smallest lakes of the lake district, not even quite a mile long from south to north, and only a quarter of a mile wide. According to my measurement it is 1,080 ft. above the level of the sea. Its form is very irregular on the south side, where the shore is formed of swamps. Three small creeks are meandering and discharging themselves into the lake—the Haumi, from the south-west; the Hangapoua, from south-east; and the middle creek without a name. Numerous observations lead to the conclusion that constant changes are going on at Rotomahana —that some springs go dry, others rise, and especially the earthquakes which are felt here from time to time seem to exercise such a changing
influence. The main interest is attached to the east shore. There are the principal springs to which the lake owes its fame. First of all is Te Tarata, at the north-east end of the lake, with its terraced marble steps projecting into the lake, the most marvellous of Rotomahana's marvels.” The two islands Pukura and Puai that were situated in the lake, equally with geyser, puia, and ngawha, were carefully described by Hochstetter, whose observations and painstaking work are a model to students of science. Of Mount Tarawera he remarks, “The chief ornament of the adjoining landscape is the Tarawera Mountain, with its crown of rocks divided into three parts by deep ravines: it rises on the north-east side of the lake to a height of at least 2,000 ft. above the level of the lake. It is an imposing table mountain, consisting of obsidian and other rhyolite rocks, and it is not to be wondered at that its dark ravines and vertical sides have given rise to many an odd story in vogue among the Maoris. Among others, a huge monster, 24 ft. long, resembling a crocodile, is said to haunt the clefts of the rock, devouring every one who dares to scale the mountain.”
The next writer that describes Rotomahana and Mount Tarawera is Domett, in his inimitable poem, “Ranolf and Amohia.” Mr. Domett was at one time Resident Magistrate and Commissioner of Crown Lands in Napier, and he had a fine grasp of Native legends, and he has made good use of them in the above poem. Domett retired from the Government service in the year 1871, and the following year “Ranolf and Amohia: a South Sea Day-dream” was published. Ranolf is a young Englishman and Amohia a Native young woman of high caste. They love one another, and, leaving the girl's home, they wander over the country and at last reach the south end of Lake Rotomahana. They see a canoe which has evidently not been in use for some time, so they untie it, and finding a paddle they move towards the Pink Terrace :—
As at the closing of a sultry day,
In search of some good camping-ground
They paddle up Mahana's Lake,
* * * *
A mighty cataract—so it seemed—
Over a hundred steps of marble streamed
And gushed, or fell in dripping overflow;
Flat steps, in flights half circled—row o'er row;
Irregularly mingling side by side:
They and the torrent curtain wide
All rosy-hued, it seemed with sunset's glow.
They continue their journey northward across the lake and they come to the White Terrace, which is thus described :—
They paddle past, for on the right
Another cataract comes in sight:
Another broader, grander flight
Of steps, all stainless, snowy-bright!
They land; their curious way they track
Near thickets made by contrast black;
And then that wonder seems to be
A cataract carved in Parian stone
Or any purer substance known—
Agate or milk chalcedony!
* * * *
Each step becomes a terrace broad;
Each terrace a wide basin brimmed
With water, brilliant, yet in hue
The tenderest delicate hare-bell blue
Deepening to violet.
This description of lake and mountain could only have been written by one familiar with both. Neither Dieffenbach nor Hochstetter has described the lake, the geyser, puia, and ngawha in greater detail than Domett has done in his inimitable 17th canto, into which the actions of two young lovers are wound with rare poetic power.
Two English writers of eminence visited Rotomahana before the great catastrophe took place, but neither Trollope nor Froude possessed any special scientific knowledge; and although their descriptions, particularly that by Froude in his “Oceana,” form delightful word-pictures of the inimitable White and Pink Terraces they contain nothing beyond what has already been stated concerning Rotomahana and its marvellous surroundings.
Since the eruption in 1886 very little has been written concerning this interesting district. In March, 1893, Mr. Percy Smith, who was at the time Surveyor-General, visited the country immediately round the site of the Tarawera eruption, and noted some of the changes that had taken place. referring to Rotomahana, Mr. Smith says, “The two lakes existing soon after the eruption [Rotomahana and Rotomakariri] have since become merged into one, and the bounds very greatly extended—so much so that instead of a surface of 25 acres for the two lakes in August, 1886, they now cover, roughly, 5,600 acres, and at the same time the waters have risen from a level of 565 ft. to 985 ft. The lake as at present existing is bounded on all sides by steep hills, which formed the walls of the great crater in June, 1886.” Since this was written Lake Rotomahana has continued to enlarge, and at present it extends from north to south more than five miles, and in its widest part reaches nearly two miles and a half, and contains an area of about 7,500 acres.
Hochstetter pointed out that the lake was fed by three streams. The only stream that is seen to flow into it at present is the Haumi, which comes from the chasm towards the south; but another stream flows into the lake abreast of the small islands known as Patiti. This stream comes from Lake Rerewhakaihu, and for a portion of its course runs underground. The rapid increase of water in the lake, and the merging of Rotomakariri and Rotomahana so soon comparatively after the eruption, suggests that the lake must be supplied largely from some underground source. Possibly the water that falls upon Tarawera and Ruawahia drains into Rotomahana by way of the chasm, so that it is likely the lake will continue to increase, and subsequently be merged with the Rerewhakaihu Lake, which is estimated to be between 30 ft. and 40 ft. above that of Rotomahana. But, as Rotomahana has only to rise a little more than 30 ft. before being able to burst through and form a channel into Lake Tarawera, an interesting problem presents itself which time alone can solve. Should the time arrive when Rotomahana breaks through into Tarawera, a dangerous rush of waters will take place that might result in serious damage to the lowlying country in the vicinity of Te Teko. But Rotomahana as a lake has plenty of room for expansion to the southward, and this it is now doing along the line where the activity at present is most powerful. The thousand steam-vents that were to be seen in 1887 have all been covered by water, but they are no doubt as active as ever. The pressure of the overlying water keeps them from exploding, but the steam-vents along the south-west sides of the lake are extremely active, and present features that imply rapid changes underneath. Along the fissure towards the south, near the place where tourists enter and leave the launch when coming from or going to
Okaro Lake, the steam-vents are powerful and excessively active; and along the entire chasm there are many signs of unusual activity, steam being forced through the rock at very high pressure.
The water of the lake is of a greyish-green colour, and contains a fair amount of mud in suspension. The lake is bounded by high walls of paleblue mud, which are easily washed away in time of heavy rain. This may account for the colour of the lake-waters; but the Haumi Stream also carries down plenty of mud—in fact, during heavy and stormy weather the stream must carry down an immense quantity of material from the soft pasty mass of the area which the stream drains.
The country, wherever it was covered with material from Rotomahana, presents a curious appearance. The blue clay is mixed with scoria that was thrown from the mountains, and they appear to have fallen together in many places. The surface becomes hard and gritty, and yet in time of rain deep ruts or gutters are quickly formed, and there appears surface-characteristics that are not seen under ordinary physical conditions. Every rut represents a drainage-basin from two adjacent slopes that may not be more than 2 ft. or 3 ft. wide, but of fair length; and the drainage from this miniature watershed and basin forms in time ruts of extreme depth, resembling a crevasse in the ice. These provide pitfalls to the unwary, and it is impossible for a horse to pass across country where these ridgelike places abound. As time goes on, these miniature-basin areas will merge, and the basins will grow fewer and fewer as erosion breaks down the ridges. In some places where grass was sown there are few ruts, and comparatively little damage to the new surface has taken place. But the lesson to be learnt is that resulting from the action of the weather upon a surface that has to be supplied with a covering of vegetation in nature's own way, and the growth of an ordinary river-basin by the merging of hundreds and even thousands of tiny miniature basins where the old basins have been obliterated presents even to-day an object-lesson of the utmost interest in the physical evolution of surface-features in a country.
At the time of the eruption the mountains presented the appearance of having been torn and wrenched by some great titanic force. The south end of Mount Tarawera, known as “The Chasm,” ran towards the lake from nearly the front crest of the mountain. This chasm is now quiescent, and but for the colour of the material and traces of scoria it would be difficult to suppose that the rift had been made within the past quarter of a century. Immediately above the chasm there is a fringe of black lava that has evidently flowed into its present position. It passes over the crest, and is lost in a dip of the mountain which has been filled with scoria and other material thrown from the craters further along the mountain. The appearances suggest that, before the chasm burst, an opening in the mountain further to the north had been made from which lava—a heavy dark lava—had commenced to flow. The late Mr. Blythe stated that he saw a stream as of moving lava, and was supported by others. Between this place and the first of the craters is a dip from which one rises to the flat, where the first crater is seen. This flat area is ridged, and shows a series of earthquake-cracks running north-east and south-west. The depressions have formed places of safety for lowly forms of vegetation, and several varieties of ferns were collected among other specimens of plants. The two craters on Tarawera are separated from each other by a kind of rock partition. The walls of the craters on the west and north more particularly show varying coloured bands of scoria and cinders, which have a
thickness in some places little short of 80ft. As this banded scoria is vertical in the side of the crater, it would seem as if the scoria had been deposited from another crater before the explosion occurred that produced the adjacent craters. The largest and deepest craters are those on Ruawahia and on Tarawera, whilst the scoria is deeper than is shown on the most southern of the Tarawera craters.
The gut or saddle that separates Wahanga from Ruawahia has crater differing from all the rest in shape and formation. The sides are formed into ledges or terraces, and the material on the platforms resembles white sand (feldspar crystals?). The two craters on Wahanga are at the eastern side, and not on the top, as in the other mountains, and the scarp can be seen by passing ships from the Bay of Plenty.
The scoria in each crater is covered at the present time with a curious lichen (Collema?). In the damper places it gives the scoria a peculiar appearance, as if coloured by aerial action, and it leads an observer to suppose that the craters were formed at a remote period rather than at a recent date.
Along the west side of the mountains overlooking Lake Tarawera a bold embattled top front with vertical sides is formed, below which the material is loose, and is made up, apparently, of the remains of the explosions from the craters on the top. The rock varieties are few, and there are no traces of mud such as is found over the country that was affected by the explosion in the Rotomahana Lake.
A great and marked change has taken place in the general surface-features of the country. The Tikitapu Bush that was destroyed has in a large measure reappeared. Fern has covered the valleys in many places, and where grass-seed was sown shortly after the eruption it has grown and provides an abundance of food for sheep and cattle. The place known as Te Wairoa, which was destroyed, is again being reoccupied, whilst most of the area in the vicinity is covered over with a variety of plant-life, some native and some foreign. An Australian acacia (A. decurrens) has become the principal tree, and its growth is so rapid that the residents of the place use it for firewood. The plants are of a lowly type, but they show how the surface is quickly reclothed if the soil is suitable.
Thus a township was overwhelmed with material from a mountain and a lake ten miles away, and to-day, after the brief space of twenty-four years, hardly a trace remains to show that such actually took place. The country is again covered with vegetation, the bare and desolate places have been reoccupied, and organic life has reasserted itself over hill and mountain and valley. The lakes Tikitapu, Rotokakahi, and Tarawera have returned to their former conditions, being either of a deep blue or green colour, so that sedimentation of the material that fell into them at the time of the eruption has been long since completed.
The ridge of land that at present separates Lake Tarawera from Rotomahana is less than a mile across, and, though bare in parts, grasses of various kinds grow well, clovers flourish, and a fair variety of native plants abound. A similar remark applies to the mountains. Two varieties of Lomaria ferns, two species of Epilobium, three species of Gaultheria, two Veronicas, a Dracophyllum, and four varieties of grasses were found, in addition to Coriaria ruscifolia (tutu), which is common towards the lower part of the mountain overlooking the lake. And this was at the end of the summer season. No doubt in spring the variety is much greater; but the specimens collected by me show that the mountain-sides are being
reclothed with vegetation adapted to the physical conditions at present existing.
An interesting question arises as to what the future of the volcanic area is likely to be with Rotomahana as a centre. When Mr. Percy Smith wrote in 1893 the lake was 985 ft. above sea-level, and had risen 420 ft. in less than eight years. Sixteen years have since elapsed, and Rotomahana has risen an additional 65 ft., has largely extended its area, and is now within 30 ft. from the lowest point in the direction of Lake Tarawera; and in the meantime much of the devastation caused by the eruption has been obliterated—so much so that a stranger unacquainted with the facts of the eruption would fail to realize that within so short a period as twenty-four years an entire district, occupying thousands of square miles, was affected by the material from a volcanic explosion, whilst tens of thousands of acres of land were covered with mud and volcanic débris and all vegetable and animal life destroyed.
And yet this process of destruction and renewal is ever active. The Tarawera eruption is not the only one that has taken place in the history of vulcanism in this Island. Similar eruptions have taken place in the Waiotapu Valley, at Rotokawa, and Wairakei, in the Waikato from Tapuharuharu to Orakeikorako, and in Taupo itself. The Taupo Plateau has been covered and built up of products from explosions such as those of Tarawera Mountain and Rotomahana Lake. Nor should the student of vulcanism separate the Tarawera country from the other portions of the volcanic district, the old as well as the new; but this aspect of the question must be left for discussion until the second portion of my paper on the Taupo Plateau is considered. There my desire is to throw out a suggestion as to the reclothing of the earth's surface with organic life following a period of great volcanic activity. It has always been a puzzle—nay, a mystery—how new plants and animals appear at the outgoing of one formation and the incoming of another. All traces of the previous forms of life are not destroyed, but new species come in and old ones die out. Does an eruption like that of Tarawera and Rotomahana afford any clue to the answer? It seems to suggest a possibility.
In times gone by explosions have been on a much grander scale than are now experienced, and much larger areas of country were affected. Organic life must have suffered, and at times have been almost destroyed; and adaptation to the new environment was enforced on the flora and fauna that were not swept away. Surely there is some probability that the life within special areas would be largely affected in this way, and when the forms of life extended from other districts and came within the limits of the conditions existing following an eruption a merging must take place so as to conform to the new conditions. Could animal and vegetable life undergo marked modification by such means? It may be possible, but it is difficult to put the matter to a test.
A separate inquiry into the botany of the Taupo Plateu may provide some suggestive matter, as showing specialization or variation from specific types; and now that attention has been called to the subject some botanist of leisure may think an inquiry on this point may not be unworthy of his observation.