Art. XX.—On the present state of Applied Science in the Canterbury Province. An Address delivered at the Annual Meeting of the Philosophical Institute of Canterbury, November 5, 1866.
Mr. President and Gentlemen,—Our esteemed President, Dr. Haast, being more than usually occupied at present in the preparation of maps and drawings for the Paris Exhibition, I have been requested to address you in his place this evening, and I have thought that it would be most in accordance with your wishes, that the subject of my address should be connected with the public works of Canterbury, to which so many years of my life have been devoted. I propose, therefore, to occupy your time, for a short half hour, with a brief review of the progress of applied science in the Canterbury Province; and in doing so, my object will not be so much to call for gratulation in respect of what has been already successfully accomplished, as to point out how much yet remains to be done, and to direct the attention of the members of the Institute to subjects of enquiry, in which they may engage with equal interest to themselves, and advantage to the colony in which we have fixed our homes.
Telegraphic Communication. Let me first call your attention to the present state of telegraphic communication throughout New Zealand.
It is but twelve years ago that public meetings were held in Otago, to discuss the possibility of establishing an overland mail between Dunedin and Christchurch—the country lying between the two towns being then a terra incognita. Within the last few weeks we have witnessed the successful laying of the Cook's Straits cable, connecting the seat of Government in the North Island with all the principal towns of the Middle Island; and have had laid on our breakfast tables the printed reports of the debates with which the walls of the legislative chambers at Wellington were echoing but a few hours previously.
It may be interesting to record the dates of the successive steps by which this result has been attained.
The first telegraph line opened in New Zealand was a short line, constructed under the direction of the Provincial Engineer, between Lyttelton and Christchurch, which was opened to the public July 1st, 1862.
The line between Port Chalmers and Dunedin was opened a few days afterwards.
These first efforts were followed by the construction of the main line through the Middle Island, from Bluff harbour to Nelson, under the direction of Mr. A. Sheath, the Telegraphic Engineer to the General Government, the communication between the extreme points just named being completed March 23, 1866.
Next in order must be recorded the erection of the line between Christchurch and Hokitika, which was commenced in August, 1865, and opened to Hokitika, one of the ports of the Western goldfields, February 14th, 1866; this line has since been extended northwards along the coast, as far as Greymouth, another goldfields port; the connexion between Hokitika and Greymouth having been established July 9, 1866.
And, lastly, the whole scheme of telegraphic communication in the Middle Island has been connected with the seat of Government by a cable laid across Cook's Straits, the first official message between the Middle and North Islands having been flashed across the Straits, August 26, 1866. The total length of telegraph now open in the Middle Island, including the line across Cook's Straits, is 986 miles, of which 199 belong to the communication between Christchurch and Greymouth.
Every new country presents special features which affect the character of its public works: this is well exemplified by the working of our telegraphs. There are two special causes of interruption to our lines which are worth recording: First, the breakage of the wire by falling trees. The trees of the New Zealand forests have no tap-roots, and depend upon each other for support; hence, if the edge of the forest is abruptly exposed, as when a river cuts for itself a new line through the bush, or when a wide clearing is made for a road, the wind soon lays prostrate the decayed trees, as well as all those which may happen to have grown with an outward inclination.
So many breakages have taken place from this cause, that it would appear to be a safer method of construction to erect the telegraph wires in the forests at a short distance from the road clearings, merely removing enough of the undergrowth to allow of the wires being strained from
tree to tree. Of course the lines would be somewhat crooked, and the points of support greatly multiplied, but the risk from falling timber would be reduced to a minimum.
The other special cause of breakage, lies in the necessity for fixing the telegraph poles, in many places, in the shifting shingle of the river beds. The only remedy for this, appears to be, to sink the foundations of the points of support below the limits of the shifting shingle, either by driving in piles, or by bedding the posts in blocks of concrete, and to diminish their number as much as possible.
By elevating the points of support to such a height that there shall be no undue strain, the Provincial. Telegraph Manager, Mr. G. Bird, has succeeded in erecting with common No. 8 wire, and maintaining without accident, spans much larger than those commonly used.
The following are the largest spans in the Hokitika line:—
|River Porter||1848 feet.|
|Valley of the Seven Springs||2122 "|
|Valley of the Broken River||3498 "|
In the latter instance, the telegraph poles are placed on the cliffs at the edge of the valley, which is so deep that there was no difficulty in giving a safe curvature to the wire, and although the action of the wind on this immense span is considerable, the wire appears perfectly equal to the strain.
Although the Hokitika line is carried across two high ranges, the passes through which are covered with snow for several months in the year, very little inconvenience has been experienced from this cause; but the working of the line has been occasionally delayed, in the winter months, by the thawing of the frozen snow which has accumulated round the insulators, by the heat of the sun, thus causing a current to earth, the insulation being restored in the afternoon, as soon as the temperature fell below freezing point.
The construction of the western portion of the line to Hokitika was attended with many serious difficulties. Upwards of fifty miles were through forests, inaccessible to horses, and intersected by dangerous rivers, whilst the weather in the Alpine ranges was so severe that during one month there were only nine days on which it was possible to work.
The cost of carriage of materials alone, amounted, in many parts of the line, to upwards of £80 per ton, whilst wages at the rate of two shillings per hour were hardly sufficient to induce the workmen employed to continue the work, in the face of the hardships and privations to which they were unavoidably exposed. Under these circumstances, the successful completion of the line across the New Zealand Alps, is a work reflecting very great credit on the Provincial Telegraph Manager, Mr. George Bird.
With the exception of the delay caused by the failure of the lines at the river crossings, the New Zealand telegraph lines may be said to have worked well since their erection; the vexatious interruptions which occasionally have occurred being caused chiefly by the great distances between the stations, and not by defective construction.
I would call your attention to the efforts now making in England to abolish retardation in the working of submarine cables. Should these efforts be successful, it is a question whether their greater efficiency would
not far more than compensate for the extra cost of using land cables, instead of suspended wires, at the crossings of our wide shingle-bed rivers, and in exposed situations, where the maintenance of a suspended wire is liable to interruption from violent storms, heavy falls of snow, or other causes.
Postal Communication. I referred just now to the defective state of our postal communication twelve years back. It is pleasant to compare our then with our present condition. We have now about fifty offices open for the receipt and delivery of mails in our own province alone; morning and evening deliveries of letters in the principal towns, and constant communication by powerful steamers with the adjoining provinces, and with Australia.
The recent opening of the Panama route is a great boon to New Zealand, as it not only puts us in direct communication with America, but brings us practically a fortnight nearer to England; and the announcement of the authorities that all letters and newspapers shall be sent via Panama, unless otherwise directed, is an earnest of the desire of the Government to avail itself to the utmost of the advantages offered by the new route.
The success which has attended the first voyages of the Panama steamers, the distance of 7000 miles from land to land, being run under twenty-seven days, is further proof, if proof were needed, of the perfection to which marine engines have been brought, although it may be doubted whether the proportions usually given to the steamers employed in long sea voyages are not calculated to ensure speed at the sacrifice of other considerations equally important.
It must be a matter of deep regret to all, that up to the present time the advantages that our province ought to derive from the visits of the intercolonial steamers, are, to a considerable extent, neutralised by the want of proper wharfage in Lyttelton Harbour. It is to be hoped that this urgent want may shortly be supplied by the works now in progress.
Roads. The level character of the Canterbury plains, and the abundance of gravel suitable for road metal, has made the construction of the main roads through the eastern portion of the province a very easy task, respecting which there is little to record of scientific interest. Some few exceptions may be here noticed.
Thus, in the construction of the Sumner road, between Christchurch and Lyttelton, the original gradient of the ascent to Evans' Pass, from Sumner Valley, was altered to correspond with the slope of the lava streams, of which the mountain is formed, by which means full advantage could be taken of the natural terraces formed by the projecting edges of these streams, whilst the road was made wider and straighter than it would have been as first laid out, and the amount of rock blasting was reduced to a minimum.
It may be interesting to glance at the nature of the channels, through which the great rivers of the Canterbury plains find their way from the hills to the sea—as they all possess, to a greater or less extent, the same features—which govern the selection of points of crossing, and as a consequence, the direction of the main lines of road running parallel to the eastern seaboard.
The general section of the Canterbury plains, taken in a direct line
from the sea to the hills, may be described as a curved line, differing but little from a dead level near the coast, but rising at a gradually increasing gradient until it reaches the foot of the hills, which, in most places, rise abruptly from the plains. On the other hand, the river beds themselves rise from the sea to the mountain gorges at a tolerably regular slope of from twenty to thirty feet per mile, running from the gorges between terraces of great height, which gradually diminish until they die away altogether, leaving the rivers to run on the surface of the plains, for a short space, after which they again sink below the level of the country, and run to the sea between high cliffs of shingle, whose height varies with that to which the edge of the plains rises above the sea beach.
Thus, with few exceptions, every one of these rivers presents a point at which it may be crossed on the general level of the country: below which it is either inaccessible on account of the cliffs by which it is bounded, or difficult to cross on account of the number and depth of the channels into which it spreads on the surface of the plains, and above which it can only be approached by long sidling descents cut in the terraces.
Between Christchurch and the Waitaki, a distance of 143 miles, the position of the southern lines, both of road and railway, has been determined by considerations of this nature, and with the following result, viz., that the main route to the south forms a tolerably accurate line of division between the swampy and well-watered belt of agricultural land on the sea-board, and the dry shingle plains, which are only suitable for pasturage. In many places the agricultural land does not extend up to the road. Thus, whilst for a distance of twenty-five miles from Christchurch, along the Leeston road, the country is fenced in and mostly under cultivation, producing largely both grain, dairy produce and live stock, the Southern Railway, which is laid out so as to cross the Rakaia river as near to the sea as practicable, is yet two or three miles from the edge of this cultivated district, and runs for miles across a desolate looking plain—without water, trees or human habitations. It has been questioned whether it would not have been better to have laid out the Southern Railway with a series of curves, running down towards the sea between the great rivers, to intersect the agricultural districts. This course would, however, have been open to very many objections. The direct line across the shingle plains is, with the exception of the river crossings, the most inexpensive that could well be imagined; whereas, the construction of a locomotive line nearer to the sea, across a swampy country intersected with a net-work of creeks, would have greatly increased the cost per mile, besides adding greatly to the total mileage.
It appears to me, that this is precisely one of those conditions of country suited to the combination of light-horse tramways with a main locomotive line, and I trust that, before our next annual meeting, we may see the experiment fairly tried, in the Selwyn district, by the construction of a light tramway leading from the heart of the district, to the main trunk line now in course of construction to the Selwyn. The line of the South road between Timaru and the Waitaki possesses an interest, as being a record of the great change which has been going on for some years past in the conditions of the country. In many places the road takes a circuitous course to avoid what some years ago were dangerous swamps, but which
are now dry pastures. Whether this is due to the gradual rising of the land, to a diminution of the rainfall, or simply to increased evaporation, arising from the destruction of the original rough vegetation, through burning and feeding off by stock, is a question which deserves attentive examination.
It may be thought worthy of being put on record, that four-horse mail coaches were first put on the North and South roads, running throughout the whole length of the province, a distance of about 200 miles, on the 10th of October, 1863.
But if there is little of scientific interest connected with the construction of the roads through the eastern portion of the province, the public works of Westland make ample amends for the deficiency; amongst them stands prominent the new road, just constructed, by the gorge of Otira, across the New Zealand Alps, connecting the City of Christchurch with Hokitika and Greymouth, the ports of the western goldfields.
The Otira road is a remarkable work, in every point of view; whether we consider the grandeur of the scenery through which it passes, the geological interest of the Alpine districts which it traverses, the engineering difficulties attendant on its construction, or the hardships manfully endured by those engaged on the undertaking, it is in every way a work reflecting credit, not only on the Canterbury province, but on all New Zealand.
Up to the commencement of the year 1865, there was no road from the Canterbury plains to the West Coast, except a very rough and dangerous path, cut across the Hurunui saddle by Mr. Charlton Howitt, in 1862, by means of which, at considerable risk, horses could be taken as far as Lake Brunner. Mr. Howitt was engaged, at the time of his death, in 1863, in cutting a track from Lake Brunner to the mouth of the Greenstone Creek, but it was not practicable for horses. It is true that horses had been taken down the Teremakau to the beach, but this could only be done when the river was low, and then not without considerable risk.
Up to the date last mentioned, but little attention had been paid to the fact that, notwithstanding the inaccessible nature of the country, a very large number of diggers had found their way into Westland, and were pursuing their vocation with considerable success.
About the beginning of 1865, however, the reports sent by the miners to their friends, were of such a favorable character, that a violent rush set in from Eastland to the new El Dorado, and the attention of the Government was directed to the best method of opening up a communication with the goldfields. To this end, Messrs. Edwin and Walter Blake were sent to improve Howitt's track by the Hurunui and Teremakau to Lake Brunner, and to explore for a line of road, in continuation, across the country between the Teremakau and Hokitika.
At the same time, Mr. George Dobson and the Provincial Engineer, were charged with the examination of the Waimakariri and its tributaries, to ascertain whether there were any passes which might afford greater facilities for constructing a road across the Alps, than that by the Hurunui saddle.
The results of these explorations were published in a report from the Provincial Engineer, dated May 15, 1865, amply illustrated with maps and sections.
In accordance with the recommendations of this report, this report, the Government at once took steps for the construction of a bridle road over Arthur's Pass, descending into the Teremakau by the gorge of the Otira. It was at first intended to construct a mere bridle track, but the importance of the new goldfields developed itself so rapidly, that within a few weeks of the commencement of the works it was decided to construct a coach road throughout. From the date of this decision, the works along the whole line of road, from the plains to the sea beach, were put in hand as rapidly as possible, and pushed forward with such energy, that by the 20th by March, 1866, the road was open for traffic from end to end, and has been regularly travelled, ever since, by four-horse coaches, running twice weekly each way; the distance of 150 miles, between Christchurch and Hokitika, being completed in thirty-six hours, including a night stoppage of twelve hours at the half-way station.
It is very difficult, by a verbal description, to give any idea of the obstacles that presented themselves to the construction of this road. Perhaps the greatest of all arose from the inaccessible character of the country; the only way of getting tools and stores to the central portion of the work, being either by poling canoes up the Teremakau from the beach, or by pack-horses travelling over the Hurunui saddle, from the edge of the plains—a journey of seventy miles, and, moreover, this had to be done in a densely timbered country, in the depth of the winter.
No pen can describe the sufferings endured by both man and beast during that terrible winter, exposed to sleet and snow and bitter frost, hardly lodged and scantily fed, whilst the working parties were liable at any moment to be cut off from communication with each other, by the rising of the rivers, By the end of July, however, a pack-horse track was opened through the Otira Gorge, which enabled supplied to be taken into the Teremakau Valley, with comparative ease, and the works in the latter valley were greatly facilitated, by the use of drays, which were carried in pieces across Arthur's Pass, and put together in the Teremakau river bed, which was used as a temporary road whilst the bush clearings were being made. As, with the opening of the tracks, greater facilities were given for the conveyance of stores to the works, the number of men employed was increased, until it lamounted to upwards of a thousand.
Since the opening of the road the work has gone steadily on, and may now be said to be completed, although, from the nature of the country through which it passes, it will always require constant attention to keep it in repair, especially in the valley of the Teremakau, which is periodically visited by dangerous floods.
The total distance from Christchurch to Hokitika, by the Otira route, is 150 miles, as above stated, of which about one hundred miles of road, from the eastern foot of the hills to the sea beach at the mouth of the Arahura, have been made and metalled between May 1st, 1865, and October 31st, 1866, at a cost, in round numbers, of £145,000, or something under £1500 per mile.
The engineering works upon this line are of a very varied nature. In some places the cliffs are scarfed out for a portion of the width of the road, the remainder being carried on timber brackets, in the fashion of Trajan's celebrated road on the bank of the Danube; in others, the line
is carried across ravines on embankments faced with walls made of timber cribbing, filled with blocks of stone.
The fords in the rivers have been protected by wing dams formed of large trees backed with boulders; whilst in many places the mountain torrents have been made passable by building timber weirs across them, and filling up their beds to a uniform level with stones and gravel. Through the swampy forest the ground has been drained and fascined, for many miles, whilst the whole length of the road has been thoroughly metalled. Amongst the bridges, that over the Taipo, 270 feet long, built upon piles, with steel shoes, driven into a mass of granite boulders, deserves mention, as being a difficult work, successfully executed, and which has, up to the present time, resisted the heaviest floods, although the stream has been at times blocked with drift timber from bank to bank.
The explorations of Dr. Haast at the head-waters of the Molyneux, the Waitaki, the Rangitata, and the Rakaia, and those of the Provincial Engineer in the upper valley of the Waimakariri, have fully established the fact, that throughout the entire length of the province there are only three real passes, viz., the Hurunui Saddle, dividing the sources of the Hurunui and Teremakau; Haast's Pass at the head of Lake Wanaka, which leads over a very low saddle into the valley of the Haast River, which falls into the sea near Jackson's Bay; and Arthur's Pass which is nothing more than a great fissure, running in a tolerably direct line from the valley of the Waimakariri to that of the Teremakau. The so-called North Rakaia Pass has no real claim to the title, its eastern face being simply a wall, rising abruptly from the valley to a height of 1500 feet, and being quite impracticable for horses or cattle; besides being at so great an elevation as to be buried deep in snow during eight months in the year. An inspection of a good map of the province will help to explain this absence of passes throughout so great a distance. The rocks comprising the central chain have, at a very early period, been crumpled up into huge folds, the upper portions of which have been denuded, leaving the remaining portions of the strata standing up in vertical or highly inclined positions, the axis of the foldings having a tolerably uniform bearing of N.N.E.
Now, it will be seen, on looking at the map, that the central chain exhibits two distinct systems of valleys, the one radiating from a common centre, situated about fifty miles north of Mount Darwin, which includes all the rivers from the north to the south of the province, giving the idea that the country has been starred, just as a mirror is starred by a violent blow; or, as in rock blasting, a set of radiating fissures is sometimes produced by a single shot; the other running parallel to the axis of the foldings of the strata, or rather following a compound course, partly on the lines of strike, and partly on the lines of the joints of the strata, like a line struck diagonally across a chess board, but following the sides of the squares, and giving to the cliffs which bound these valleys a peculiar rectangular appearance, resembling ruined masonry, on a gigantic scale.
Now, it will be observed that, with the exception of that of the Hurunui, none of the radiating valleys run directly across the main chain, which, at the heads of the Rakaia and Waimakariri, stands up like a
wall, barring all further progress. Haast's Pass, the lowest, and probably the easiest of all, does not extend across the northern branch of the chain, but leads to the coast by following the westerly course of the Haast river. Arthur's Pass, does not, as it were, cross the range in a direct line, as does that by the Hurunui, but leads along it from one radiating valley to another; the Waimakariri and the Teremakau overlapping each other, to the extent of about twenty miles.
Thus it will be understood, that these three passes occur under three distinct sets of conditions. Haast's Pass, at the head of the Wanaka Lake, is both in the line of one of the great radiating valleys, and also in the direction of the axis of the great foldings of the strata, these two causes in combination, having formed an unusually low gap in the mountains. The Hurunui Pass, on the other hand, is one of the fractures running directly across the range, whilst Arthur's Pass is simply a fissure parallel to the planes of stratification, from which the rock, already bruised and shattered, when the surface of the country was crushed up into the huge foldings, before referred to, has been gradually removed by glacial action, and by the weathering process constantly going on over the whole face of nature.
The depth to which the great valleys have been filled up with shingle and debris, may be inferred from the interesting sections prepared by Dr. Haast, of the comparative fall of the Canterbury rivers, and from those prepared by the Provincial Engineer, in connection with the Otira road. These sections show that the river-beds form beautifully regular curves, from their sources, to the rock-bound gorges through which they issue to the plains, which would not be the case if the rock bottom were sufficiently near the surface to check the downward flow of the wet shingle.
Before leaving the subject of the Otira road, I would call your attention to the great value of the aneroid barometer, as an instrument for ascertaining altitudes. During the Provincial Engineer's explorations of the West Coast routes, a set of flying levels across the country was taken by aneroid observations, a single instrument only being used, and the weather being exceedingly unfavorable; yet the results compared very satisfactorily, both with the altitudes afterwards obtained with great care, by Dr. Haast, and with the actual heights as determined by the spirit level, after the opening of the Otira road. In laying out the line across Arthur's Pass, where the road descends 750 feet in a very short distance, measured in a straight line, the gradients were determined entirely by the aneroid, the observer creeping through the dense scrub on his hands and knees, and fixing the position of the line, at every few chains, by the readings of the aneroid; the line thus laid out requiring but little subsequent alteration, when the clearing of the timber had given an opportunity for the correction of any irregularity in the gradients.
Railways. Passing from ordinary roads to railways, we have to record the completion of a first instalment of the Southern Railway, constructed under the superintendence of Mr. W. T. Doyne, M.I.C.E., which was opened for traffic as far as Rolleston, about fifteen miles from Christchurch, on the 15th October, 1866. On the Lyttelton and Christchurch Railway, which has been open for traffic between Christchurch and the Heathcote wharf, since December, 1863, the works of the Moor
house tunnel have made steady progress, only about 240 yards remaining to be driven at the present time, out of a total length of 2838 yards.
Independently of the interest attached to these tunnel works, in a geological point of view, as affording a complete section through the side of an extinct volcano, they are of importance as an example of engineering difficulties successfully overcome.
The syphon employed for the drainage of the upper half of the tunnel, is probably the longest of which there is any record in the history of tunnel works, being upwards of half-a-mile in length; whilst the system of ventilation employed, viz. that of conducting the smoke and foul air through a flue formed by a horizontal brattice, into an upcast shaft near the tunnel mouth, has proved perfectly effective. It is worth remarking, that the engineers of the Mount Cenis tunnel have at last found it necessary to employ a similar means of ventilation, the supply of compressed air forced into the face of the work, being insufficient to drive out the smoke which filled the tunnel like a series of walls of dense fog.
It may be laid down as a leading axiom, with regard to the ventilations of drives mined with gunpowder, that although fresh air may be driven in by machinery, so as to produce a healthy atmosphere for the miners, the smoke from the shots cannot be driven out, but must be drawn out, by creating a vacuum in the direction in which the smoke is to be drawn; the attempt to force smoke, by an air-current in the rear, producing generally a dense fog, in which candles are of little use.
A very curious fact connected with the bratticing in the Lyttelton tunnel may be here mentioned. The brattice is formed of inch boards laid on joists running across the width of the tunnel, and housed at each end into the solid rock. Both joists and boards rapidly became covered with fungus, and require to be replaced from time to time with new material. Although, after the first year, portions of the brattice repeatedly fell from decay, these falls invariably happened on Sunday, when the men were absent from the work, no fall having taken place whilst the men were at work, until quite recently, when the decay of the timber had rendered necessary an extensive renewal of the brattice. The explanation of this curious fact is probably the difference in temperature on week days and Sundays; the furnace fire at the foot of the upcast shaft being allowed to go out on Saturday night, and not being lighted again for twenty-four hours; the hot smoke which occupied the flue during the working days, being replaced on Sunday by a comparatively cool atmosphere.
I may here mention, that a tunnel is now being driven in France on the new line of railway, between Lyons and Roanne, under Mont Sauvage, which divides the valleys of the Rhone and the Loire. This tunnel will be two miles in length, and will be driven from five shafts, of which the deepest will be upwards of 600 feet in depth. From the geological character of the district, it is anticipated that the rock to be bored through, will be of the hardest description; and it is stated in scientific journals that in one of the shafts the difficulties met with are such, that a progress of two inches in twenty-four hours is all that can be accomplished.
It will be interesting to watch the progress of this work, especially in reference to the question of how far boring machinery can be introduced
with advantage in tunnelling through rocks of equal hardness with those met with in the Lyttelton tunnel.
Some curiosity has been expressed as to the correctness of the alignment of the two ends of the Lyttelton tunnel, and the method employed for checking any error that might be committed in the direction of the work.
The system employed is very simple. A permanent mark is fixed in the centre line of the tunnel, on a tower built on the dividing range, nearly midway between the two ends. A transit instrument being placed on the meridian of the tunnel, in a position to command a view into the tunnel, as well as of the tower on the hill, it can be seen at once whether the flame of a candle placed on the centre line of the work, inside the tunnel, is in a vertical plane with the mark on the tower. But it is also desirable, in case of error, to have the means, not only of correcting, but of calculating the amount of such error, and this can readily be done. The permanent mark on the central tower consists of a batten six inches wide, with a black stripe one inch wide down its centre. The eye piece of the transit instrument, being furnished with five vertical wires, placed at equal distances apart, the value of the space between any two wires, at a distance equal to that of the mark on the tower, can be ascertained by reference to the width of the batten, which thus gives a scale by which the error in the position of a light, placed in the tunnel under the tower, can be rated with great exactness.
Although it is not probable that any important extension of our railway system can be undertaken at present, it is satisfactory to know that the surveys of the Southern Railway have been carried down to the Waitaki, and connected with those made by the Railway Engineer of the Otago Province, and that the necessary reserves have been made, so far as the lines run through land belonging to the Government.
Rivers. During the last few years great changes have taken place in the channels of some of our large rivers, both on the East and West Coasts. The Rangitata has, for some years past, been scouring out for itself a new channel down what is known as the Deep Creek, the original main river-bed being now almost deserted by the water. It is worth putting on record that this great change, which seriously affects a large extent of pastoral country, had its origin in the cutting of a ditch to form a sheep boundary, and the run of water thus established has gradually attained such dimensio [ unclear: ] s as to cause the diversion of the greater part of the river from its original bed. The Waimakariri, which used to deliver the great bulk of its waters through the channel on the south side of the Kaiapoi Island, has shifted its course into the north channel (the quantity of water in the latter stream being shown, by gauging, to be three times that in the former one), overflowing its banks in many places, and seriously injuring the navigation of the river, by the amount of shingle brought down by the freshes. At the same time, the river has threatened to break through its banks, about nineteen miles from Christchurch, and to flow down to that town along channels which, although long since dry, at some distant time have carried no inconsiderable quantity of water.
It is impossible to over-estimate the value of a continued series of observations made, from year to year, to ascertain the nature and extent of
the changes going on in the courses of our rivers, and I would earnestly request each of the members of the Institute to assist, so far as lies in his power, by making careful measurements, from permanently fixed points, of all alterations taking place in his own immediate neighbourhood.
Arterial Drainage. Passing from natural to artificial watercourses, there is but little progress to record with regard to arterial drainage. With the exception of the Rangiora swamp (which has been partially reclaimed by a carefully planned system of drains, calculated, when completed, to reclaim 7000 acres of swamp land), the drainage works of the province are of no interest, in a scientific point of view, except as showing the mischief that may be done, by attempting to drain extensive districts, without keeping distinct outfalls for the upland and lowland waters.
I would wish to direct the attention of the members, to the efforts being, made, in England, to enable landowners to obtain powers for draining through private properties, and for the relief of districts which have been water-logged, to use an expressive term, by the injudicious erection of dams and weirs for obtaining mill power, often to the infliction of great injury upon the surrounding properties.
Such legislation is no less needed here than in England; and I may remark upon a peculiar feature of our low-lying lands, which introduces unusual difficulty into the question of main drainage.
It is, that the natural watercourses through the swamps and half-dry lagoons, are, in most cases, above the level of the adjoining land, running between embankments which appear to have been formed by the gradual deposition of silt in comparatively still water. So generally is this the case, that in the neighbourhood of Christchurch, it will almost always be found that a rise in the ground marks the position of an old watercourse, the original source of which has been cut off by the gradual deepening of the beds of the rivers by which it was fed.
It will, therefore, be readily understood, that the natural watercourses cannot be used for the drainage of our swamp lands, but that new lines must be cut for that purpose; and it is precisely the interference with private property involved in this course, that has led to so much difficulty and litigation in the attempts to reclaim the swamp lands in the province.
For some years past, the Provincial Engineer has been engaged in recording the levels of the country, as ascertained during the progress of the various road and railway surveys, the several sections having been all taken with reference to a common datum, viz., ordinary high-water springs at Sumner Bar. It is proposed, gradually to extend these levels over the whole province, as opportunity offers, and to establish permanent stone bench-marks in every road district, for future reference. It is interesting to observe that a similar work is now in progress in France, for the purpose of affording accurate data for engineering surveys of all kinds, and it would be difficult to overrate the value of the information thus given to the public, or the facilities it affords for ascertaining, almost at a glance, the difference of level between distant points, which it is required to connect for the purpose of drainage, water supply, or other engineering works, in which the rate of fall is an important element.
Health of Towns. From the drainage of the country, we pass, by
a natural transition, to that of, the towns, and to those questions which may be classed under the general head of sanitary engineering. And here it must be confessed with regret, that beyond the abolition of the cesspool nuisance, there is no progress whatever to record.
Although numerous schemes of drainage have been proposed for the two principal towns, viz., Lyttelton and Christchurch, nothing has yet been done towards their realisation. This is the more to be regretted, as the Municipal Councils of both towns having approved of the system of removing the solid sewage, at short intervals, by scavengers, the question is narrowed to that of the disposal of the house slops, the outfalls for which would be the sea in the one case, and the rivers Avon and Heathcote in the other.
Practically, therefore, the only question to decide is, whether, they shall be carried down the streets in the open side channels, or in underground pipes.
Now, it is worth while to glance for a moment at the physical conformation of the two towns, as they may be considered extreme types of exactly opposite cases.
Lyttelton is built in the crater of an extinct volcano, on a series of spurs and gullies, the streets stretching up the steep hill-side to the height of 200 feet above the sea, to which there is ample fall from every part of the town. But Lyttelton, unfortunately, has no water supply beyond what is derived from a few deep wells near the beach, which are exhausted in the summer months, making it necessary, at times, to bring water in coasting vessels for the use of the town. In this case, the work to be done is to provide, and raise, an ample supply of water to the upper part of the town, and to flush the gutters from the street mains, the fall in the gutters being so great that they can be effectually cleansed by this means. The water might be taken from the artesian springs in the tunnel, or from the Heathcote river; in the latter case being brought from the plains, through the tunnel, in pipes.
Christchurch, on the other hand, is an example of a totally different combination of circumstances. The town may be said in general terms, to lie on a plain, sloping gently to the eastward; the western side of the town being about 23 feet, and the eastern about 9 feet above high-water mark.
But, although, the fall of the ground to the eastward is ample for underground drainage, which can be brought to a regular, gradient, the irregularities of the surface are so great, that the fall of the street gutters is in many places barely sufficient to allow the water to run, much less to allow them to act as channels for offensive matters.
Here, then, the proper course is to lay underground pipes to carry off the surface drainage, instead of allowing it to become stagnant and putrid in the back yards of the houses, or to form offensive pools in the street gutters. And, by way of compensation for this expense, Christchurch has a magnificent and unfailing water supply in her artesian wells, the water being met with at from 60 to 90 feet below, and rising to a tolerably uniform level of 25 feet above, high-water mark; the artesian water throughout the greater part of the town, rising several feet above the surface. It is worth noticing, that the artesian water was tapped first in Christchurch, February 10, 1864.
If, however, we can say but little in praise of the sanitary arrangements of our towns so far as drainage is concerned, there are other points on which satisfactory progress has been made. A fair number of the streets in our towns are formed to their permanent levels, and metalled either with shingle or broken stone; and, in Christchurch and Lyttelton, the principal streets are provided with paved gutters, and raised footpaths paved with gas tar concrete, which appears to answer well, and not to be injured by the heat of the sun as is the case in hotter climates.
Near most of the towns of the province, suitable plots of ground have been set apart for cemeteries, so as to avoid, from the first, the evils attendant on intramural burials, and the care taken of these cemeteries is a pleasing circumstance connected with their management.
Introduction of Gas. It may be mentioned that the streets of Christchurch were first lighted with gas, December 13, 1865.
Lighthouses. The lighthouse at Godley Head, at the entrance of Port Lyttelton, was first illuminated, March 31, 1865. This makes the seventh light on the New Zealand coasts, in addition to the harbour lights.
I have extended this address so much beyond my original intention, that I can only now glance at a few miscellaneous subjects.
Iron-founding. It is worth recording, that iron-founding was commenced in Christchurch, by Mr. John Anderson, in May, 1857, at his establishment in Cashel-street, which has now attained considerable importance in New Zealand, and offers great facilities for the construction of almost all kinds of mill work and machinery.
Employment of Steam Power. Steam power has been employed, to a very considerable extent, for some years past, for various purposes.
The necessities of the Western goldfields, have led recently to the erection of several powerful engines, in the neighbourhood of Hokitika, which are employed in draining the deep sinkings, and raising water for gold washing.
The Lyttelton Times has been printed by steam power since October, 1864; and the Press, another daily paper, is printed by one of Ericson's caloric engines.
Steam cranes have been in use upon the Railway Wharf, at Heathcote, for nearly three years.
It may be mentioned, that amongst the items of intelligence brought by the last September mail, is the erection of steam cranes on the quays at Paris.
A powerful steam engine is in use on Timaru beach, for hauling up the cargo boats used in the lighterage service.
And here, I must conclude this brief, but/I trust, tolerably comprehensive sketch, of the present state of applied science in Canterbury. If, on the one hand, there are many shortcomings to be regretted, I think it may also be said that, as yet, we have made few mistakes; whilst with scanty means, and a comparatively small population, we have succeeded in introducing amongst us, and making familiar as “Household Words,” most of the great inventions of the civilised world. We have our telegraph through the country, and our submarine cable connecting our capital with the seat of Government in the Northern Island. We have our great tunnel in construction, and our road across the New Zealand
Alps. We have our goldfields, our coal mines, our founderies, our broad acres tilled with the steam plough, our clipper steamers, our mail coaches, and our locomotive railways, and we have all this in a country which, fifteen years ago, was an almost unknown land, but which is now, by God's blessing, the happy home of prosperous thousands of our fellow men. And let me impress on your minds that this measure of success has been due, in no small degree, to the superior education of Canterbury men, as compared with that of the usual class of settlers in a new country; and to the stimulus given to applied science in Canterbury, by the prosecution of the trigonometrical survey, the establishment of permanent departments of public works, of geology and natural history, and the appointment of a board of education, as one of the departments of the Provincial Government; and, in conclusion, let me earnestly hope that every member of the Institute will endeavour to realize the responsibility which rests upon him, to do all in his power to carry on the work so well began, and that each succeeding year will bring fresh subjects of interest to record, and fresh successes to incite us to greater exertions, in behalf of science, and of our adopted country.