INDIA AND INDIAN ENGINEERING. (continued 2)

As to Measures and Weights, in Upper and Western India we employ the lineal, square, or cubic foot as the unit for our estimates and calculations; in Madras, they use the cubic yard. Our lineal units are generally understood, except, perhaps, the mile; natives generally give distances in kosses, which vary from 1 to 2½ miles. The acre is employed in Government papers, but is not known to the people, who measure land by the beegah, which varies greatly in different districts. The weights commonly used are the maund, seer, and chittack, which are practically held to be 80 lbs. avoirdupois, 2 lbs., and 2 oz. respectively.

There is as great variety in India as in other countries in all local weights and measures, and the people are as obstinate and suspicious there as in England, and elsewhere, about any changes being made,—a fact too often forgotten by the decimal and metrical doctrinaires in their zeal to ensure a theoretically perfect system of standards.

Let me now say something of the mode of executing work generally, before going on to the subject of special engineering constructions. The first thing that strikes the engineer from England is the primitive simplicity of the working appliances, and the total absence of the elaborate and costly plant judged necessary for executing great works in Europe. Steam engines, steam cranes, steam pumps, steam pile-drivers, tramways, even such things as hand-pumps, horses, carts, and wheelbarrows are rarely used. This has arisen from the comparative cheapness of manual labour, from the difficulty of procuring skilled subordinates, and from the dearness of fuel. Now that the first two causes are greatly modified, and the extensive works lately undertaken have necessitated recourse to European appliances, the engineer going out to India should devote special attention to this subject, for he will often have to teach his subordinates the use of such things as I have mentioned. Great works have, however, been constructed in India without them, and will still be so for some time to come. Earthwork, for instance, is constructed almost entirely with wicker baskets as the sole means of carriage; yet few countries have had so many massive embankments thrown up. Petty contracts are readily taken for this kind of work, in which case the whole family of the workman, down to the child of three years old, will help to swell the mass to be raised. A system of payment at the rate of a cowrie paid on the spot for every basket of earth carried is very popular, several hundred cowries going to a rupee. For such banks, the earth is almost always taken from side cuttings to save the expense of a long lead, as the land is comparatively of little value. The earth is dug with a phowrah, the common native tool, which is at once a spade and a hoe, and an excellent tool it is.

For getting water out of foundations, and for lifting water generally either for irrigation or otherwise, several ingenious contrivances are employed. For a lift not exceeding three or four feet, and where the hole or excavation is not too small, a swing-basket covered with leaves or matting is used as a bale, being swung by two men. I have often seen water lifted in this way from 12 to 16 feet, in three or four stages, by as many pairs of men, the baskets being swung together in exact time, and the quantity lifted one stage being about 1800 gallons per hour.

For higher lifts, there are three machines commonly employed—the paecottah, or lever bucket, used in Bengal (the counterpoise on the shorter arm of the lever being a heavy stone or a lump of clay); the churus, or chursah, common in the North-Western Provinces, a large leathern bag drawn up by bullocks; and the Persian wheel, or endless chain of buckets, also worked by bullocks, and everywhere employed in the Punjab, which has been in use in the East for at least 2000 years, and is one of the most effective and ingenious water-raising engines yet invented.

The native carts or hackeries are drawn by bullocks or buffaloes, and are exceedingly primitive vehicles. They have no springs—often no iron tires to the wheels—and, except the axle-pins, have generally no iron at all in them. But the advantage is that they can go over any rutted track that does duty for a road, and that if they do get broken, the nearest carpenter can repair them. That, of course, is the real difficulty in introducing English improvements into India, that if your fine carts or pumps get broken, who is to repair them?A

I now come to a very interesting subject to the Indian engineer, which involves several specialities, and applies more or less to all the constructions we shall consider afterwards in detail—I mean the subject of Foundations. Of course the general principles of constructing foundations are the same everywhere, that is, you must secure, if possible, a firm and unyielding substratum. If you cannot find this naturally supplied, you must use artificial contrivances, either by proper distribution of your weight to be supported, or by preventing any lateral spreading, or undermining from the action of water. For this purpose in England we have recourse to piling, or concrete, or iron cylinders and screw-piles. How is it in India? Well, there, as a rule, piles won’t do; first, because timber is scarce and dear; second, and chiefly, because it is exposed to so many causes of decay that it would quickly rot. Iron cylinders and screw-piles have been a good deal used lately; but generally in India, both these and the timber piles are superseded by the employment of Cylinders of Brick masonry, varying in diameter inside from 3 to 12 feet, and sunk either to a firm stratum below, or to such a depth as to be safe from scour,—the weight being borne in this case by the friction against the sides. A sufficient number of wells are designed to carry the superincumbent weight, whether it be a house or the pier of a bridge, and the whole series being sunk to the required level, and as close together as possible, the tops of the wells are arched over, the arches are all connected together by slabs of stone or other arches, and on this artificial platform the superstructure is raised.

To sink a well, the néemchuk, or well-curb, a ring of wood from 9 to 18 inches thick, is laid on the ground, the masonry built upon it about 4 feet high, and left to dry. The sand inside is then scooped out, and the well descends gradually, when another 4 feet are built up; the sand is again scooped out; and so on, until the required depth is reached. So long as there is no water met with, and the soil is sand, the work is easy enough, the only care being to see that the excavation proceeds regularly and evenly; but when the water is reached, and as it deepens, the process is a slow one. A huge sort of hoe (called a jham) is used, which is worked from above into the soil, and then hoisted up with its load; a Persian wheel or a churrus being also used to keep the water down as much as possible. Sometimes blocks of wood or kunkur are met with which impede the descent of the well, and then a diver must be employed,—a man who descends without any diving apparatus, and can stay under water an alarming length of time.

Since the construction of so many great railway bridges, in which these cylinders have been sunk to a depth of 50 feet, various improvements have been introduced. The wooden curb has been replaced by one of wrought iron, with a sharp-cutting edge, into which are bolted below several rods of inch iron running through the masonry, and connected at intervals by flat iron rings, so that the whole cylinder is well bound together. A Sand Pump has also been invented, worked by a steam-hoist, to take the place of the old native jham. This, and another machine for the same purpose, called Fouracre’s Well Excavator, you will find described in the ‘Professional Papers’ and the Roorkee ‘Treatise.’

Sometimes, instead of a series of separate wells, the whole mass of a pier has been built in a block, with hollows at intervals, and sunk together by several parties of well-sinkers. In this way the piers of the great Solani Aqueduct, at Roorkee, were constructed and sunk 20 feet; but this work requires very experienced men, and is subject to such risks that, as a rule, separate wells are preferred.

Such work as the above can only be carried on when the river is low, and the current very slack, and this may be a good place to speak of the general nature of such Indian Rivers. I refer chiefly to such streams as the Ganges, Jumna, Indus, and others, as there are few things of more vital interest to the Indian engineer.

They rise in the region of perpetual snow, generally from glaciers at a height of over 20,000 feet, and make their way to the plains (receiving numerous affluents on the road), as great torrents with numerous rapids, and quite unnavigable, except in particular places. On emerging into the plains, which they do very suddenly, the bed changes, first from boulders to shingle, and then to sand, and the stream cutting deep into this soft soil, becomes more and more charged with silt, especially as the lessening slope of the country checks the onward velocity. Thenceforward, the river is a sluggish stream, pursuing a tortuous course between low, flat banks, and full of shoals and quicksands, until near its mouth, where it parts into numerous channels, and forms a vast delta reaching to the sea. Owing to the vast quantity of silt brought down by these rivers, which elevates their beds and during the inundation season is freely deposited on both banks for some distance inland, it follows that these streams, in the lower portions of their course, often run on a ridge, and not at the lowest points of their valleys,—just like the Po and Mississippi, which are retained between artificial dykes.

These rivers are at their lowest in the cold season; and in December, January, and February, their navigation is attended with the greatest difficulties. From March to June, the increasing heat of the sun melts the snow in the higher ranges, and the rivers rise rapidly. In June, July, and August, the monsoon rains increase their volume to a prodigious extent. Their banks are often inundated far inland, and the yellow turbid waters carry down more silt than ever; the increased velocity of the current, acting on the light sandy soil of the sides and bed of the channel, cuts away the banks and scours out shoals in one place, and then at the next bend a temporary check will throw down enormous quantities of this silt, and the stream shoots off in a new direction altogether. I have seen the whole of the Indus concentrated in a not very deep channel 1000 feet across; six months later I have been in a boat on the same spot, and was unable to see either bank from mid-stream. In one year I have known it cut its way inland a full mile, measured perpendicular to the thread of the stream.

It is these violent changes in velocity and direction, and the soft and treacherous character of the soil, that make the question of foundations in water a peculiarly difficult one in India. The sudden shifting of a shoal may dam up the archway of a bridge, and the increased velocity in the narrowed waterway acting on such soil, often scours out a hole 30 feet deep in a single night. Almost every rainy season in India sees failures and disasters on this score, and the most carefully considered design may be a mass of ruins in twenty-four hours. The Bengal mode of dealing with these difficulties is to carry down every pier-cylinder, whether of masonry or iron, to such a depth as either to rest in the firm soil below, or to be absolutely beyond the reach of any possible scour, but to put no flooring or curtain walls by which the stream can possibly be checked and incited to tear up the bed. The Madras system is to be content with a much smaller depth of foundation, but to provide, by means of a flooring and apron walls, a compact dam of masonry solidly bound together, front and rear and from shore to shore, which shall be proof against any action of the stream. The subject is one which has excited much discussion, but is too long to enter upon here. You will find it treated of in the works already quoted.

I have now described the most important specialities of Indian foundations, and have to ask you to follow me in the first section of what I may call special engineering constructions, viz. Buildings, or rather dwellings, such as houses, barracks, churches, and the like. The subject is, of course, a very extensive one, and I only propose here to draw attention to those buildings which the Indian engineer is generally called upon to construct. First, then, let us take Indian Barracks, that is, barracks for English soldiers in India, as they are not only the most important buildings that you will have to deal with, but there are many vexed questions concerning them which are still far from settled, and which apply equally to all dwellings erected for Europeans in an Indian climate.

In the earlier days of our Indian empire, the barracks constructed for the European soldiers were often built on ill-chosen sites; the rooms were low and a great deal too crowded, and drainage and conservancy scarcely thought of; the consequence was a frightful mortality, which often reached the high figure of 70 to 90 per thousand. As the important subject of sanitation received more and more attention in England, it was not likely it should be neglected in India, where a tropical climate aggravated the results of neglect of sanitary laws, and where every English soldier who died cost the Government a large sum of money to replace him.

At the same time that attention was thus roused, the conquest of the Punjab and the necessity of quartering a large number of troops in that province to defend the most exposed frontier of the empire, made the subject doubly important, while it gave a field on which to carry out the results of recent investigations. Large sums of money were accordingly spent on the barracks at Mean Meer, Sealkote, Nowshera, and other new stations. They were all single-storied buildings—each company of 100 men having a barrack to itself, consisting of six wards, each 48 by 24 feet, and 24 feet high, with double verandahs on both sides, besides rooms for the non-commissioned officers. The men were to sleep in the wards, and to dine in the inner verandahs. A reading-room was also supplied at the end of each barrack. Wash-houses and privies were arranged in separate buildings near the barracks.

These buildings were certainly a great improvement on anything hitherto erected, and were decidedly not open to the charge of being overcrowded. Unfortunately, however, the Punjab has a cold season as well as a hot, and in the winter months the men complained that it was almost impossible to keep themselves warm; while even in hot weather, the high winds and dust found their way through the numerous doors and windows, and the barracks were anything but comfortable residences.

Nor did they prove at all healthy, for cholera and intermittent fever played sad havoc among the troops in more than one season at Mean Meer. This was not, however, owing to any fault in the barracks, but to what was an error in the choice of site for the cantonment; and attention is drawn to it because the instance is instructive, and has more than once been repeated. Apparently under the idea that there was something in the very presence of vegetation which might engender malaria, a flat, bare, dreary-looking site was selected, totally devoid of all vegetation, and with water 40 to 50 feet below the surface; while, from the presence of a kunkur or stony stratum a few feet below the top, it has been found impossible to get a tree to grow to a respectable size. It may be taken as a rule that the presence of healthy vegetation shows a site favourable to human beings as well as to trees and crops, and that such sites as that of Mean Meer should be carefully avoided in future.

Several committees were subsequently appointed to consider the question of barracks, and finally an officer of experience, under the title of Inspector-General of Military Buildings, was appointed to collate the various information collected, and to prepare standard plans of barracks for the various stations at which the Government of India had determined, on strategic grounds, to maintain a permanent force of British soldiers. It should be remarked in reference to this point that erroneous impressions often prevail in the public mind. It is often asked, why are troops retained at stations which are notoriously unhealthy? Why are the British troops not all kept at the hill stations, where they enjoy a European climate all the year round? Now, the first use of having troops at all is unquestionably that they should be ready for action at the points where trouble is likely to arise; those points are the great cities where, in the East as in the West, the mauvais sujets of the empire are generally found congregated; and all our principal cantonments have been located with this view. It is true that the railways have done much to abridge distance in India, as elsewhere. But not to mention how easily a railroad is disarranged in time of war or revolt, the railway system must be extended at least five-fold before it could help us much on this point, while to allow revolt to rage unchecked, for even twenty-four hours, in such cities as Patna, Benares, or Lucknow, until troops could be brought by rail from the nearest hill station, would be a frantic proceeding.

But the fact is that it is very questionable whether a continued residence in the hills would be beneficial to the health of all English soldiers, while there is no doubt that the hill stations are not at all popular with the men themselves. Private Tommy Atkins is insensible to the poetry of mountain scenery; he dislikes the incessant rain from June to September; he hates being unable to take a walk without having to go up or down hill; and he misses the excitement of a large native city. There is no doubt, however, that, as occasional residences, the hill stations are most valuable, and the Government has shown its appreciation of this fact by the large expenditure now being incurred on the two new Himalayan stations of Chakrata and Raneekhet.

You will find plans of the most approved forms of barracks, as at present sanctioned, in Vol. II. of the Roorkee Civil Engineering Treatise. These buildings consist of a single main ward, with one verandah all round, and are to be double-storied as a rule; the upper story being used as a dormitory, the lower for day-rooms. Separate rooms are provided for the sergeants, and separate sets of quarters, of course, for the married men. In the plains, space is to be provided at the rate of 7½ running ft. (of wall), 90 superficial ft., and 1800 cubic ft., per man, the wards being 24 ft. high. These buildings are constructed of brick or stone, as the case may be; the roofs are iron girders with brick arches between for the verandahs, and iron trusses covered with a double layer of tiles for the main wards.

Several ranges of barracks on the Government standard plans have been erected at Allahabad, Saugor, Jullundur, Peshawur, and other stations; but it cannot be said that the results have been at all commensurate with the large cost incurred. The heat and glare are greatly complained of, and in more than one instance it is believed that a return to the old temporary thatched barracks was urged. Nor have the new barracks apparently proved more healthy than the old ones; cholera stuck so closely to them at Allahabad that for some months they were absolutely deserted, and it is understood that Peshawur is no better off. Of course, it is not meant to suggest that the new barracks engendered cholera, but merely that a site unhealthy in itself has not been made less so by the erection of large and expensive buildings.

In the station where I have been quartered for eight years, the barracks were little more than temporary sheds run up just after the Mutiny, and which have not been replaced by regular buildings because it is not thought necessary to retain troops there permanently. Yet in these crowded sheds, troops have been healthier than in any station in the country.

To understand the special difficulties attending the construction of Anglo-Indian dwellings, it is necessary to revert again to the characteristics of the climate of Northern India, in which by far the largest number of our troops are quartered. The seasons of Northern India (say from Benares up to Peshawur) are the cold, the hot, and the rainy season; or, more exactly, the cold, the dry-hot, and the moist-hot seasons. In November, December, January, and February, though the sun is always powerful, the temperature of the air is pleasant during the day, and not too hot for a long day’s cricketing or shooting on foot; the nights are really cold, and occasionally even frosty. A good deal of rain also falls in the Punjab generally about February, and fires are required in the house often all day long.

In March, the hot winds begin to blow; strong breezes from the west, often rising to gales, bring up clouds of dust, and the atmosphere has the temperature of a glass furnace; from 7 A.M. the wind blows often up to midnight, and the temperature of the outer air at night varies little from that of the day. I have often known it 100° at Lahore at midnight. This lasts till the middle of June, when thunderstorms usher in the south-west monsoon, or rainy season; rain falls in torrents, the air is saturated with moisture, and though the thermometer falls several degrees, the languid, moist heat is far more trying to the constitution than a higher temperature when the air is dry. The rains end in September; October is generally fine, the mornings and evenings are cool, and then follows the cold season already described.

Now to apply these facts to our subject.

As a mere question of comfort, it has been found that a building constructed with walls of mud or sun-dried brick, with a good verandah all round, and with a thick roof of thatch, is certainly the most comfortable. It is cooler in the summer, warmer in the winter, and a good thatched roof is perfectly water-tight. But such a roof is always exposed to danger from fire, and both roof and walls require perpetual repair in the rains; while those Indian pests, the white ants, besides snakes and other vermin, increase and multiply to an alarming extent in such a building. Stone is scarce and expensive, except in a few localities, so brick is the material usually employed for permanent buildings, and the thatched roofs are replaced by tiles or concrete. Such buildings, however, become insufferably hot during the day, and numerous doors and windows are provided to allow a sufficient volume of cool air to enter during the cooler hours of the night; they give rise to one of our chief difficulties, for, during the whole of the hot weather, these openings must be kept closed for ten or twelve hours at least, to exclude the heated external air, and if so closed, some special means of ventilation ought certainly to be provided.

It is not, however, easy to effect this, for the simple reason that the air inside the building is cooler, and therefore heavier, than that outside, and thus will not pass out easily by apertures above, which also generally admit quite as much dust as fresh air.

As these numerous doors and windows evidently give access to a great deal of heat, even when closed, it seems desirable to enquire whether fewer openings would not be a better arrangement, and there can be little doubt that this would be the case, if a proper system of ventilation were at the same time contrived by blowers, or otherwise, as will be hereafter noticed. It is also probable that thicker walls of hollow bricks, or even double walls, would be a great improvement over the present thin walls of solid brick. But brick-making machines are still in their infancy in India. The tiled roofs are also doubtless a great cause of the heat of these barracks. And as thatch is out of the question, it seems very desirable to find some non-conducting, non-inflammable substance, which should be interposed between the tiles and joists.

It may be noted that, amongst the natives, underground apartments are not uncommon, to escape the great heat of the summer. In the fort at Lahore, an extensive system of such tykhanas (as they were called) was found on our capture of the place, and they were certainly much cooler than the rooms above ground; but the difficulties of providing proper ventilation and light would be great, and they would probably not be healthy for Europeans.

The subject of what is the best description of building, both as to design and materials, for Europeans in such a climate as India, is indeed still an open one, and admits of great discussion. Neither our barracks, churches, nor private houses are as yet satisfactory, and as to their architectural appearance, the less said about that the better. The Gothic churches generally built in our Indian stations are insufferably hot. In that at Mean Meer, it was not uncommon to hold the service, even in the early morning, outside the church and under its own shadow! Most of the private houses in the various cantonments are simply hideous, and even the best of our public buildings, law courts, town halls, &c., are anything but adapted to the climate. Imitations of Classical, Italian, and Gothic architecture are plentiful everywhere, but few attempts have been made to adapt any of the features of Oriental architecture to our Western requirements. Yet who can gaze on the beautiful domes and minarets of the Taj Mehal or the Jumma Musjid, or the graceful arches and bold cornices of the Motee Musjid, without admiration and envy? It is much to be desired that the whole subject should be taken up and carefully studied; but so long as we have so little originality even in England, we must have patience in India.

To return to our barracks. During the hot season, the air inside is rendered more bearable by the employment of punkahs or pendant fans, which, being swung from the roof and pulled to and fro by manual labour, afford a very grateful relief, though, of course, they do not really lower the temperature of the air. Besides this, during the dry heat, tatties, or screens of grass, are hung in some of the doorways to windward, and, being kept saturated with water, fresh air is thus introduced, which is often, during a strong breeze, from 10° to 20° below the external temperature. But this contrivance is of course useless during the rainy season, when the external air is already saturated, and when often there is not a breath of wind stirring.

About three years ago a committee, of which I was a member, was appointed at Roorkee to consider the question of ventilating and cooling barracks and other public buildings in India. It was pointed out that the present arrangement of punkahs and tatties cost Government annually a very large sum; that the results were not believed to be at all commensurate with the cost, and that it was desirable to see what improvements could be introduced.

Many interesting experiments were made, both as to the best modes of hanging and swinging punkahs, and as to the possibility of dispensing with them altogether by using blowers, similar to those employed for ventilating mines, which are to some extent already used in India under the name of thermantidotes. It was found that a system of blowers, with tubes for conducting the air into the barrack-rooms, would certainly be useful for the purpose of ventilation, but that they would not enable punkahs to be dispensed with, for they could not produce the same sensation of coolness as a punkah, except by keeping the whole body of air in the room in movement at an extremely rapid rate by an extravagant expenditure of power, or by throwing cooled air in, in sufficiently large masses, as in the case of a tattie with a strong breeze blowing. Now, although it was easy to produce the breeze artificially during the dry heat, it was of no use during the rainy season, unless some artificial means could be found of cooling the air otherwise than by evaporation. And there appears no means yet known to science of effecting this in such quantities as are here required, and at such a cost as will not be ruinous. It is true that many schemes have been proposed, and some tried successfully, on a small scale, such as the use of ice, ether, ammonia, &c.; also condensing machines, such as Dr. Arnott’s; but it is believed that the problem has never been solved on a large scale yet.

Of course, the utility of blowing in fresh air for ventilating purposes is not questioned. It has been carried out in several public buildings lately erected in India; but to blow it in even during the three hot dry months, in such quantities as to cool, as well as ventilate, the whole interior of a large barrack, is expensive work; for a whole set of barracks, comprising from fifteen to thirty different buildings, separated from each other by considerable intervals, several steam engines and an enormous quantity of tubing would be required; and the cost of such things in India is almost ruinous.

It seems probable, therefore, that the old system of punkahs will be found, for a long time to come, the most efficient and economical; but their form, construction, and mode of pulling have been the subjects of much discussion. As to the form, the committee above mentioned recommended, after a variety of experiments, that the punkah should be a rectangular framework of wood and canvas, 12 to 18 inches wide, with a heavy fringe 18 to 24 inches deep; that a system of punkahs should be rigidly connected so as to swing evenly without jerking; that the best effect was produced when they moved through an arc of 5 feet, with a velocity of 2½ feet per second; that no machine had been brought to their notice equally effective and economical with a man’s arm, but that a heavy pendulum, if properly connected with a series of punkahs, might be useful to ensure regularity of swing.

The number of machines or contrivances for pulling punkahs, of which models, drawings, or sketches were forwarded to the committee, was extraordinary. A few were ingenious, but complicated and apt to get out of order; the majority were designed by men ignorant of the first principles of mechanics, who thought that a pendulum was a prime mover, or that the weights of a clock wound themselves up.

Much of what I have said above in regard to barracks applies, of course, to other buildings as well. As Government engineers, you may have, besides barracks and their subsidiary buildings, to build or repair court-houses (commonly called kucherries), rest-houses of various kinds on roads or canals for the accommodation of the establishment, possibly a museum or a college, or a lieutenant-governor’s palace; and chapels and churches. In all these buildings the executive engineer is often called upon to prepare the original design, and if he has any architectural skill, may have an opportunity of distinguishing himself. As I have already hinted, I cannot say that we have succeeded in our attempts at Anglo-Indian architecture. The leading idea a few years back was, apparently, that a barrack was the unit, or standard, or germ of all architectural designs; that a barrack was necessarily a rectangular parallelogram with four walls and a roof; that the addition of a stuccoed Grecian portico, with a cross and green venetians to the windows, produced an excellent Roman Catholic chapel, and that if you wanted a Protestant church, you had only to omit the cross and add a tall, square tower. However, we have grown beyond that now, and produce excellent copies of Gothic churches, which would be very nice if they were not so hot; and in some of the Bombay public buildings, there has been a considerable amount of originality in the adaptation of the Gothic to Indian requirements. There is, however, still plenty of room for any young candidate for architectural honours to develop original talent in this direction. I would only say to him, for goodness’ sake try to be original, and don’t be content with slavish copies of buildings erected in Europe four or five hundred years ago for a totally different climate. If you cannot be original (and doubtless the genius of originality is given but to few), then study the noble specimens of Eastern architecture that are still left to us, both in India and other eastern countries, and strive to comprehend the meaning and intent with which that style was designed; you may then catch something of the spirit of those great builders, and produce something at least suitable to the climate and the country, and creditable to the taste, which does not form a grotesque excrescence out of harmony with everything around it.

Private houses are almost invariably one-storied in Upper India; the rooms are at least 20 feet high, with numerous doors opposite each other, and small windows above for ventilation purposes. Each bedroom has always a bath-room attached to it. A verandah runs all round the house. The roof is either flat and covered with stucco supported on beams and joists; or it is pitched and covered with thatch, which is much the cooler arrangement. The floors are of polished lime, called chunam; the doors are double; the walls are white or colour-washed—never papered, as it is difficult to get the paper put on properly, and it is apt to peel off in the rains. But there is no reason that it should do so; and I strongly recommend you to get a practical lesson in paper-hanging and wall-colouring and painting before you go out, for you will find the knowledge exceedingly useful; it is simply impossible to get that kind of work done out of the Presidency towns.

Such buildings as racket-courts and swimming baths you may also have to erect occasionally; but I don’t know that there is anything special to say about them, except that the former are always open, with white walls and black balls, and that the front wall should look to the west, so that you may be screened from the sun in the evening. Of course you can have a morning court on the other side, if the station is rich enough to afford it.

Every executive engineer is supposed to be consulting engineer and architect to the public generally, and the civil authorities of the district in particular, and if the magistrate is an energetic man (as he generally is), you may have to prepare designs for market-places, serais (or resting-places for native travellers), municipal offices, clock towers, and the like; and if you are of a mechanical turn, you may be sure that you will be consulted about the machinery employed in the jail manufactures, where you will find some mechanical appliances that will considerably astonish you.

The Water Supply of a range of barracks is, as a rule, derived from wells, which indeed is the only practicable course in the very flat plains of Upper India. The water is generally good and wholesome, and the supply sufficient. This is, indeed, the general source even for all Indian cities. In only a few have proper waterworks been as yet constructed, by which a supply can be delivered under pressure. Even in Calcutta, the works are not yet completed.

The question of a proper water supply for native towns is daily assuming more and more importance, especially since it now seems pretty clear that there is a close connection between impure drinking water and that terrible scourge the cholera. Waterworks have been designed and carried out in the case of a few important towns like Poona, but the majority of towns cannot afford to pay for expensive conduits, filtering beds, pumps, and reservoirs, while they might be able to pay for simpler schemes. In these as in other similar cases, I would impress on you the necessity of mastering principles and thinking out of a groove—I don’t mean neglecting details, but turning your attention to what is essential, and ignoring what is merely accidental.

For the privies, the dry-earth system of conservancy, common all over the East, is universal, and, if properly carried out, is no doubt the best and healthiest. Such a system, however, it is almost impossible to work properly in a large crowded city, and there is no doubt that a regular system of sewers is greatly to be desired in such cases. That of Calcutta is only partially completed. In Bombay and Madras, complete schemes have been devised, but I believe are not yet commenced. The cost of such works is again the obstacle, as well as the prejudices of caste among the people; the want of surface fall in so many cities is also a difficulty, as great expense would have to be incurred for pumping.

There are no Gas Works except at the Presidency towns, and as coal is only found in a few places in India, other cities must wait until some one can devise a mode of manufacturing gas cheaply from vegetable oils, which seem the most practicable source of supply in India. The subject is an important one.

India abounds in rivers, streams, and watercourses of various kinds, and therefore the subject of Bridges is a very important one to the engineer; but before describing any of the permanent structures that have been built, it may be useful to say a word as to the temporary expedients employed on lines of road, when money is not forthcoming for the more expensive forms of construction. The first of these is a sort of Irishman’s bridge—it is no bridge at all; you go through the water instead of over it, by means of Paved Causeways, which are often employed on watercourses which contain no water for the greater part of the year, and are only flooded occasionally. The banks are cut down to a gentle slope on each side, and a pavement or solid flooring of masonry or concrete is built to afford a firm roadway for vehicles. If the water is too deep or the stream too strong, the traveller must wait till the flood goes down. You will find a good account of such a pavement across the River Soane in No. 2 of the ‘Professional Papers.’ It is a mile long by 12 feet wide, and answers its purpose very well.

On many of the great lines of road, Boat-Bridges are in use during the low-water season, which are taken up and replaced by ferry boats during the rains. The boats used are the ordinary native boats, with a platform laid on balks and saddles; but they are often troublesome when the river is falling, owing to the necessity of removing some of the boats before they are left high and dry. Cylindrical Pontoons are preferable in this respect, and are often used. There is a pontoon bridge over the Jumna at Agra, and a very fine one at Cawnpore, over the Ganges. You will find descriptions of these in the ‘Professional Papers.’

On the Hill roads, temporary bridges are very common. Some are very simple, consisting of a single suspended cable, on which is a sort of travelling cradle in which the passenger sits, and is hauled across by tackle from the shore end. Others consist of a rope for the feet and two others for the hands, the three being kept apart by triangular sticks, and if you are of an acrobatic turn of mind, they are convenient enough. More ambitious specimens have a suspended platform of bamboo 3 feet wide; and a neat Wire rope bridge of 200 feet span was built over the Jumna two years ago by some young officers who went out, with the help of the native sappers.

You will find another peculiar kind described in the ‘Treatise,’ and in No. 166 of the 4 ‘Professional Papers,’ put up by Major Lang, R.E., on the Hindustan and Thibet road. These are Sanghoos, consisting of beams weighted with stones, and gradually projecting one over the other until they meet in the centre. A Rope Suspension bridge worth study, over the Chenab, is described in No. 202 of the ‘Professional Papers.’ I would also draw your attention to the account of the Iron Suspension bridge over the Beosi at Saugur, described in No. 30 of the ‘Papers,’ erected forty years ago by an infantry officer with the unskilled labour of the district, and using materials procured on the spot. It is a good specimen of the way in which an officer is often called upon in India to exercise his mother-wit, and dispense with the ordinary means and appliances.

Of more permanent bridges, Timber structures are not much used in the plains, because wood is generally very expensive, and the extreme heat and damp loosen the joints and threaten decay to the timbers. You will, however, find several described in the books so often referred to, notably one over the Barra river, near Peshawur, by Lieutenant (now Major) Browne, R.E., one of my assistants at Roorkee lately.

Masonry Bridges of brick and stone are common enough, and you may often have to construct them. You will find several described in the ‘Papers,’ and the descriptions of the Morhur and Markunda bridges are especially good and suggestive. The piers and abutments of such bridges are generally founded on well-cylinders in the way I have already described, the number varying from three to ten according to the weight and size. In the bridges on the Lahore and Delhi Railway, great economy of construction was attempted by making each pier of one single well-cylinder, 12½ feet diameter inside, supporting a pair of lattice girders carrying a single line of rails. Now, as these were sunk from 40 to 50 feet below the bed, and had an additional height of some 20 feet to the girder above, the stability of such a long slender column was somewhat doubtful; and when the river scoured out its sandy bed down to the clay stratum in which the cylinder rested, the force of the stream, acting with such a leverage, threw over several of the piers;—at least, in this way I interpret the failures that occurred in these bridges last year. Had each pier been composed of two cylinders (one for each pair of girders and line of rails), with the two braced diagonally together, they would probably have stood.

I have not spoken of the calculations necessary for the Discharge of these rivers, and the Waterway of these bridges, because it is too long a subject to be treated of in a lecture. I will only say here that in no one single point is the Indian engineer so liable to make mistakes; there is nothing that requires so much study, and failures on account of insufficient waterway are of every-day occurrence in that country. And even when your bridge is built, and you have good reason for believing the waterway to be ample, so treacherous are these streams, that their course may change in a single night, and your abutments may be taken in reverse. In the bridge over the Sutlej, thirty-eight spans of 110 feet each were provided for the stream, and yet, when I saw it, not a drop of water was going under the bridge; the stream had shifted while the bridge was being built. Twenty other spans have since been added, the embankments have been made very massive and defended by spurs and groins at a great expense against the action of the river; yet there is no certainty that the river may not attack the embankment at some other point in the breadth of its valley (which is 5 miles across), and force its way through, leaving the bridge high and dry. By the last mail I see that one of the piers has failed, and all traffic is stopped.

Of Iron Girder Bridges there have been many fine specimens erected since the railways have been begun. Except a few small ones which have been constructed at Roorkee, they have all been made up in England, sent out in pieces, and erected on the spot. I especially commend to your notice the paper on the Tonse Bridge, in the ‘Professional Papers,’ as giving an excellent idea of the difficulties of this kind of work.

So much, then, for bridges. I now turn to the very important subject of Roads. Great progress has been made within the last twenty years in providing India with roads, but thousands of miles are still wanted before the road system can be considered anything like complete. The cost of carriage in many parts of the country is still enormous, owing to the wretched state of the unmetalled tracks, and whole districts may be starving while plenty reigns in those adjoining, owing to the same cause. However, these are questions with which the young engineer at least has seldom anything to do; his work begins when the construction of the road is decided upon. The rules regarding the laying out and construction of roads are of course the same in India as in other countries. I will only dwell on characteristic specialities. Of the construction of the earthwork I spoke in my last lecture. The Metalling employed is kunkur, already described, and various kinds of stone used in macadamizing in the ordinary way. Heavy iron or stone rollers, drawn by bullocks, are usually employed, but steam road-rollers have lately been introduced in Calcutta, Bombay, and even the wilds of the Central Provinces.

The Grand Trunk RoadB runs from Calcutta to Peshawur, a distance of 1600 miles, passing through the Rajmehal hills by some very heavy works, then on to Benares, Allahabad, Cawnpore, and Delhi, thence to Umballa, and Lahore, and Jhelum, by massive embankments; thence for the last 160 miles to Peshawur it is carried by some of the heaviest and most difficult works in the world. The designer and constructor of the whole line was Lieut. (now Colonel) A. Taylor, R.E., C.B., director of the attack at the siege of Delhi.

The Hindostan and Thibet road is another fine work which you will find described in the books. It is carried right through the hills from Kalka at the foot, viâ Simla, up the valley of the Sutlej, and is about 300 miles long; but only the first 60 miles are open for wheeled traffic. Sometimes it is carried but little above the level of the river, then it ascends a hill-side by a series of steep zigzags, then it goes boldly through a rock by a heavy cutting or short tunnel, then through a magnificent forest of deodars, then by the side of a vertically scarped hill, 2000 feet down, in which the road is either blasted out of the solid rock or supported by iron bearers let into the rock, and carrying a timbered floor. Probably no road in the world offers such fine scenery to the traveller. The officer who did most of the work on this road was Major Lang, R.E., my locum tenens at Roorkee. Before leaving the subject of roads, I may draw your attention to two or three instruments used in tracing hill roads, which you will find described in the ‘Treatise’—the Madras Clinometer, and De Lisle’s Clinometer.

It was in 1849, I think, that the first short experimental line of Railway was opened in India, between Bombay and Tanna, and soon afterwards the then Governor-General, Lord Dalhousie, issued his famous memorandum laying down the principles which were to be adopted in the construction of the great imperial lines. That great statesman had been President of the Board of Trade, under Sir Robert Peel, during the time of the English railway mania, and had been an eye-witness of the reckless manner in which money had been squandered by the system, or rather no-system, which had characterized the construction of the English lines. From that at least his famous minute preserved India. It prescribed the chief lines to be laid down, the gauge to be observed, and various other points essential to prevent the public from paying for the rivalry of competing interests. The money was chiefly raised in England by the various companies, but the Government guaranteed a minimum dividend of 5 per cent. per annum to the shareholders, in return for which it was to exercise a complete control over the work, through its own consulting engineers. This divided responsibility doubtless had great disadvantages, and it has since been thought preferable for the Government to borrow the money itself, and to undertake the construction of the lines through the P. W. Dept.; but at that time Government was not in a position to undertake the work, and the money subscribed to make railways could not of course be diverted to any other purpose, as would probably have been the case in the event of war, had Government borrowed the money itself. At any rate, the main lines have been constructed, though doubtless at a higher cost than was anticipated, and their opening has been attended with incalculable advantage to India, both in a military and political, as well as a commercial, point of view.

The East Indian Railway runs from Calcutta up the valley of the Ganges, by the great cities of Burdwan and Patna, near Benares, to Cawnpore, Mirzapore, and Allahabad, and thence to Allyghur and Delhi, a distance of 1040 miles. Agra is served by a branch line from the Toondla junction. There is also a branch line, 220 miles long, from Allahabad to Jubbulpore, where it joins the Great Indian Peninsula line from Bombay, a distance of 600 miles. The Eastern Bengal line runs for 120 miles from Calcutta to Kooshtea, whence it is now being continued towards Assam. Another line runs from Bombay across India to Madras, whence a line runs down the coast to Trichinopoly. From Delhi the main line proceeds to Saharunpore, Umballa, and Loodiana, to Lahore, a distance of 330 miles, whence a line of 210 miles runs down to Moultan. There is also a branch line, 50 miles long, from Cawnpore to Lucknow, and a few others with which I need not trouble you.

The new lines now being projected, and to be constructed by the Government itself, are the line from Lahore to Peshawur, 265 miles, one from Moultan to Kotree, down the valley of the Indus, 600 miles; one from Agra, through Rajpootana, to Indore; and another from Delhi. It has been resolved to adopt a mètre gauge for these lines, and to construct them with the severest regard to economy, and the Government engineers, military and civil, have doubtless a fine field before them.

To return to the lines already opened; they comprise some of the finest engineering works in the world. On the East Indian line, are the great iron bridges over the Jumna at Allahabad, and those over the Tonse and Soane, besides very heavy embankments and severe rock cuttings in the new chord line through the Rajmehal hills. On the Lahore and Delhi line, are the heavy embankments between the Jumna and Sutlej, and the bridging of the Jumna, Sutlej, Beas, and Markunda rivers. The continuation of this line towards Peshawur by the Government engineers will involve works of great difficulty and magnitude in the rocky country between the Jhelum and Indus, and the bridging of those two rivers, besides the Ranee and the Chenab. The passage of the last river alone will task the highest engineering skill, as that of the Sutlej has already, and for the same reasons,—the exceedingly capricious character of the stream, the sandy nature of the bed and banks, and the enormous quantities of silt brought down by the waters.

On the Great Indian Peninsula line are works of at least equal magnitude, though of a different kind, foremost among which stand the great inclines of the Bhore and Thull Ghats, by which the railway ascends the steep barrier of the Western Ghats by a series of zigzags, inclines, curves, and tunnels, which render those works unequalled in the world. On the Thull Ghat, for five continuous miles there is a grade of 1 in 37, in which occur many severe curves; while the Bhore Ghat incline is 19 miles long, and in that distance has no less than thirty tunnels.

The Rails on all these lines are of the usual double-headed pattern, weighing from 66 to 90 lbs. per lineal yard, and laid generally in chairs on transverse wooden sleepers. These sleepers are either of one or other of the woods that I have already described, sometimes kyanized or burnettized; but large numbers of creosoted fir sleepers have also been imported from Europe, and a certain number from Australia. The Punjab line is almost entirely laid on Greaves’s patent Pot sleepers, with which doubtless you are acquainted. The advantage of such a roadway is of course the indestructibility of its material (iron); its disadvantage, that the cast-iron sleepers are apt to get broken, and that the rigidity of the roadway is bad for the rolling-stock at high speeds. But there is no doubt that the life of a timber sleeper in India is very short, and that it is very expensive to renew them; and a good wrought-iron permanent way, that shall not be absolutely ruinous in first cost, is still a desideratum.

The Locomotives employed on the Northern lines more nearly resemble those in America than in England, as they have to burn wood instead of coal. A huge spark-catcher is hoisted over the chimney, as serious accidents at one time were common from the blazing sparks of wood out of the uncovered funnel; and a cow-catcher is placed just in front of the smoke-box, to take up stray cows or buffaloes, who will get on to the line in spite of the fencing. The engine-drivers are all Europeans, I think, at present.

Fences are made of cactus or other hedges, or of the usual wire line, or often simply of a mud wall and ditch.

There is nothing particular to say about the Stations, which are similar to those in England, with some adaptation to the requirements of the climate.

The Passenger Carriages are a great deal too much like those in England, and are generally very hot and uncomfortable. The best have double roofs, with cane backs and seats; but none have punkahs or tatties; and it is only lately, and at the instance of a very stern reminder from Government, that any serious attempt has been made to render passenger carriages for European travellers more comfortable in the hot weather. On the Great Indian Peninsula line, however, there are very comfortable saloon carriages, with movable berths, and bath-room and W.C. attached. Considering that from Bombay to Calcutta or Lahore is a journey of some seventy-five hours, it is evident that these things are serious matters in India.

That the results of these railways have been of the greatest benefit to India in both a political and military sense, it would be impossible to deny. Their educational and social value, too, to the people at large have been great, and indirectly they have doubtless added much to the wealth of the country. But only one line, I think, pays more than the guaranteed 5 per cent., so that for all the others, the Government pays a heavy charge annually for the advantages offered by the railways, and this charge has of course to be met by taxation. The traffic, too, is increasing very slowly, and it seems that much is still wanting to assist its development to a much larger extent than heretofore. One reason for this is, doubtless, that a great portion of the goods traffic consists of articles, such as grain, of large bulk and small intrinsic value, which will not bear high transit charges. Another cause is that the natives, though travelling far more than was anticipated, have not yet learned to travel to the same extent as Europeans.

One mode of increasing the inducement would, I suggest, be to make the railway fares more uniform, and the tickets more easily procurable than at present; and this mode, indeed, would apply to English, as well as to Indian, lines. There seems no more reason that you should have to buy your ticket for a railway journey five minutes before starting, and all in a scramble in front of a little pigeon-hole, than that you should be forced to purchase your postage-stamps at the General Post-office only, and just five minutes before the post goes out. I don’t see why all journeys, up to a certain number of miles, should not be performed at one uniform rate of charge, and by tickets procurable at the nearest stationer’s, and available for any line in the kingdom. Such a measure would be a great convenience to the traveller, would prevent him in India from being cheated, as he often is, by the native railway clerks, would effect a considerable economy in the railway office establishment, and, where the lines are all under Government control, ought to be carried out with very little trouble.

But we must go on to the leading speciality of all Indian engineering, I mean, the subject of Irrigation Works. Of course there are other countries in which artificial irrigation is extensively developed,—more indeed than in India,—notably, for instance, in the provinces of Piedmont and Lombardy, in the kingdom of Italy, where they are in advance of us both in the economical distribution of water, and in all legislative questions affecting the administration and rights of, and property in water. But in no other country but India have works been undertaken on so gigantic a scale; and it is in the dealing with such vast bodies of water, and their carriage over such great distances and in the face of so many impediments, that the specialities of Indian irrigation works really consist.

Now, in order to give you a clear idea of the subject, I must begin by premising a few remarks of an agricultural and financial character. India is almost entirely an agricultural country. It is true she has great mineral resources, but these are as yet undeveloped. She has had valuable manufactures, and there is no reason she should not have them again; but for many ages past and for as many to come, she has been and will be almost entirely agricultural.

Again, half of the whole Government revenue is derived from the land. It is called a land tax, but is really a land rent; that is, rent paid by the occupier or cultivator, as the case may be, to the State as the great landlord. This has been the case all over the East from time immemorial; the only ownership in the land belongs to the Government, although the occupier or cultivator often has rights of occupancy which are almost as inalienable as the right of the State.

This being the case, it is evident that the Government is as much interested as the people in the productiveness of the harvest; for if the harvests fail, the people not only starve, but cannot pay the land rent, and the Government has to feed thousands of hungry people with an empty exchequer. Owing to the absence of roads and railways in years gone by, any failure of the rains in a province produced the most appalling distress, and the people died by hundreds and thousands.

Hence, so long back as 300 years ago, the Mahomedan emperors, commonly called the Great Moguls, took a great interest in artificial irrigation, and under the direction of a Mahomedan “Royal Engineer,” one Aliverdi Khan, several canals were opened out. Some of these, after falling into disuse from various causes, have been re-opened and improved under the British Government, and are now known as the East and West Jumna Canals, the one being 110, the other 500 miles, long. Then the Government commenced a great work of its own, the Ganges Canal, of which the main channels alone are 700 miles long, and the first-class distributaries 3000 miles more. Since then, the Bari Doab Canal has been completed; the Sirhind, Soane, and Sardah canals are in progress, and others are projected.

It will perhaps give you a better idea of this kind of works, which are all similar in character, if I briefly describe the largest of all, and the one with which I am best acquainted,—the Ganges Canal. This canal takes out of the River Ganges at Hurdwar, where the river leaves the hills and enters the plains, by an artificial channel 200 feet wide and 20 feet in depth, the water having a depth of 10 feet, and the fall of the bed being 2 feet per mile. This gives a volume of water of nearly 7000 cubic feet per second,—rather more than the Thames at Richmond, I think. The canal, flowing onwards, crosses three great hill torrents, two at a lower level, and one by a level crossing, and finally reaches the valley of the Solani, which it passes by an aqueduct three miles long, revetted with masonry throughout, the Solani river itself being passed by a bridge, which gives it 750 feet of waterway. After crossing this valley, 20 miles from its head, the canal arrives on level and comparatively easy ground, and pursues its way along the watershed of the country between the Ganges and Jumna rivers for another 30 miles, broken only by sundry falls and locks, and spanned by several bridges. At 50 miles from its head, it divides into two branches, of which one runs down to Futtehgurh, the main line continuing to Cawnpore, and throwing off other branches to Bolundshuhr and Etawah. From these main lines, the principal distributaries run on both sides, nearly parallel to the channel, and throwing off in their turn other minor lines,—until the whole country is covered with a network of irrigating channels, conveying the water to every field.

Thus you will see that this and other irrigating canals differ from an ordinary navigation canal, such as you have in England, in two very important particulars. First, the irrigating canal has a running stream of water which is gradually expended as we follow its course, and so its channel diminishes in size; secondly, it is dug on the highest line or watershed of the country, so as to secure a command of level for irrigating the whole area.

Now, as to the use to which this water is applied; you will understand that there are two harvests in Upper India: the rubbee, or spring harvest, which is reaped in March or April, and consists mainly of wheat; and the khurreef, or autumn harvest, which is gathered in September, October, or November, and consists of rice, sugar, Indian corn, and various tropical products. All these require steady and constant irrigation, and they get it from the spring and autumnal rains, or from wells, during the average normal seasons; but if the rains fail and the wells run dry, they are dependent on the canals, and even when the season is regular, the supplementary irrigation from the canal greatly increases the yield of the crop.

The Soil of Upper India is generally a light friable clay, excellent for wheat, but absorbing a great deal of water. In Bengal, they have a rich mud extending to a great depth, and of such fertility that three crops are often grown on it in a year. In the Central Provinces, there is the black cotton soil, which is, I believe, disintegrated trap or granite. Across the Indus, again, we have a hard stiff clay, which, though not good for wheat, is valuable for many crops when well watered. I notice this question of the soils here, because it is an important point for the engineer when projecting a new canal, for all these soils require different quantities of water.

In designing a canal such as has been described, we must fix the head at a point high up on the course of the parent river, first to get a command of level, so that our canal may run on high ground; and next because, in the higher portion of its course, the river water is free from silt, and the river bed is more stable and less liable to the caprice of the stream, which, lower down, might abandon our canal mouth.

Having fixed on the point of departure, then comes the question, how large is our channel to be? That depends, first, on the quantity of water we can get out of the river when at its lowest; secondly, on the slope or fall we give to the bed of the canal. The minimum quantity of water is, of course, determined by observation, and this has hitherto practically fixed the capacity of canals in Northern India, because the spring crop grown in the dry season is so much the more valuable of the two; but in later projects, an additional capacity of channel has been allowed, so that an extra supply of water may be admitted in the autumn, when the river has plenty to spare.

As to the fall of the bed, or the Velocity to be allowed to the artificial waterway, that is a question depending chiefly on the nature of the soil. Several of the Indian Canals have been designed with too high velocities, and the consequence has been a cutting and scouring of the banks and beds, which have seriously endangered the various masonry works in their course. On the other hand, if you give too little velocity, of course you have to go to a greater expense by making a larger channel to carry the same quantity of water, and you won’t have velocity enough to carry forward the silt held in suspension, or to prevent the growth of weeds, a serious evil in the tropics. On the whole, it seems now generally admitted that a velocity of 2½ feet per second is about what should be aimed at, though a compromise of conflicting interests, in this as in other cases, has often to be made.

When, owing to the slope of the bed being less than that of the country, the slope, if continued, would bring the canal bed too high, and embankments would have to be made, it is evident that the bed must be lowered by an artificial Fall or Rapid, made of such material and shape that the mass of water may flow over it without injury, and take up a new level below. The best forms of falls and rapids have been the subject of great discussion amongst Indian canal engineers. The Ogee fall in use on the Ganges Canal is now superseded by the Vertical fall of Colonel Dyas,—the principle of which is that the shock of the falling water is received into a cistern sunk below the bed, so as to act as an elastic cushion. A grating of wooden bars, inclined at an angle, and fixed along the crest, is also generally added. These bars act like the teeth of a comb, and, by dividing the water into filaments, greatly reduce its force.

If you want to navigate your canal, Locks must be provided as well as falls; but the difficulties of navigation up stream are very great, and the traffic on all these canals, with a current of some three miles an hour, is in a very undeveloped state. It is doubtful whether it is not impossible to combine satisfactorily the requirements of both irrigation and navigation in the same channel.

At the heads of your branches or main distributaries, Regulating gates will be required with sluices, by which the supply of water may be divided, increased, or diminished, as the case may be. A similar work will be required at the head of the canal where it leaves the river. The tail generally ends in a fall or rapid, by which the water is discharged into a river or nullah with a scour to clear away the silt.

You will find details of all these works in the Roorkee C. E. ‘Treatise.’ Besides these, Bridges of communication will be wanted for the roads crossing the canal; Rest-houses (chokees) for the use of the establishment; Escape heads for discharging surplus water; Inlets for the reception of cross-drainage; and other works.

One chief object of carrying the canal at a high level is that it should interfere as little as possible with the natural Drainage lines of the country; but it is occasionally indispensable that it should cross some of them, and it may cross them under three cases:—1. When the bed of the canal is higher than the bed of the drainage line. 2. When it is lower. 3. When the two beds are on the same level.

In the first case, the canal is carried over by an Aqueduct, which may be of masonry or iron, according to the size of the canal, and which must allow sufficient waterway underneath for the passage of the drainage line when in flood.

In the second case, the drainage line is carried over the canal by a Super-passage, which is in effect an aqueduct, only that here you have to provide waterway above the canal for the river in flood. The canal, if necessary, may be carried below it by an artificial fall of the usual construction.

The third case rarely occurs in practice, and never when it can possibly be avoided—there are the same objections to it as in the case of a Level crossing on a railway. When it has to be done, the method of doing it may be understood by an explanation of the Rutmoo level-crossing on the Ganges Canal at Dhunowrie, six miles above Roorkee. A regulating bridge, with sluices, is fixed across the Canal, just below the junction. A series of flood-gates hung between piers is fixed across the Rutmoo, on the down-stream side of the canal; these gates fall outwards by a hinge at the bottom, and are held upright by a catch, which can be easily knocked out, and when thus held up, they retain the canal at its normal level. When the Rutmoo is in flood, the Canal sluice-gates are lowered to prevent the flood water rushing down the canal, and choking it with silt or débris. At the same time, the Rutmoo flood-gates are lowered by knocking out the catches, and the whole flood water pours across the canal, and flows down its own channel. When the flood is over, the sluices are raised, and the flood-gates also one by one, the pressure of the water being taken off by dropping planks down grooves in front, provided for that purpose. Such a work of course requires the presence of an establishment to manage it, and is very liable to be damaged by carelessness on the sudden occurrence of a flood.

Well—the canal having been made and filled with water, how are we to get the water into the fields? First, it flows down the main distributaries, and then into secondary channels, which are laid out at proper slopes, and of a size varying according to the amount of water and the area to be watered. From these it is passed by pipes of wood, iron, or earthenware, under the banks on to the fields, which are divided into squares (kyarees), into which the water is passed seriatim.

As there is generally less water than is required, village watercourses are all filled in their turns; thus one set will be filled on three days of the week, and another set on three other days, and so on. The water rate is levied by the canal officer according to the area irrigated, and the kind of crop taking it, as some crops want more water than others, and are also better able to pay for it. Such a system is obviously open to many objections, for it entails endless labour in measurement, perpetual watchfulness, and much dispute and interference, besides great waste. Some system has therefore long been sought by which the water should be measured out at the head of the distributary channel or village watercourse, and charged off like beer or wine. Hitherto, however, all attempts to do this in India have failed; chiefly, because we cannot find any practical machine that will not get out of order and cannot be tampered with, by which a uniform discharge may be secured in a given time under a varying head of pressure. Could this be done, it is obvious that if a head or opening of a given capacity were left open for a certain time, we should know exactly how many cubic feet of water had been sent to a particular village. Lieut. Carroll, Royal Engineers, a very clever and promising officer, invented a module (as it is called), which you will find described in the ‘Treatise,’ and which has been the nearest approach to a machine of the above kind.

By comparison of the discharge of his canal at different points and measurement of his irrigated areas, it is obvious that the canal officer can collect data for determining what is styled “the irrigating duty per cubic foot.” This varies much with the soil, the rate of evaporation and other data, but on the best-managed canals, will amount to the irrigation of 300 acres for each cubic foot per second of water discharged at the main head. This is the rate on the Eastern Jumna Canals; on others it is not nearly so high, and in new projects about 200 are usually assumed. There are various other statistical data for canals of great value, which you will find treated of in the ‘Professional Papers’ and the Roorkee ‘Treatise.’

In Southern India, the canals are of less elaborate construction, owing to the more permanent character of the rivers in the lower portions of their course, and to the abundance of excellent stone found there, while in Northern India we have to be content with brick. The chief object of engineering skill in a Madras system of canals is the Anicut or Weir thrown across the river at the point of departure, by which a head of water is secured for the supply of the canals. Many of these weirs are elaborate and costly affairs—that over the Godavery is a mile and a half long, and the weir over the Soane, now under construction, is little less. I show you on the plan the one over the Kistna, which is a good example of its kind. You will see that the body is composed of rubble stone, defended by ashlar from the action of the water, and resting partly on shallow wells, and partly on the bed of the river itself. This shallow character of foundations on sandy beds, to which I have already alluded in a former lecture, is certainly a peculiarity of Southern Indian engineering; but you will see the long slope or apron of stone in rear of the weir, where the action of the water is most severely felt after being checked in its onward flow, and caused to whirl and scour. Very severe action takes place here for some time after the weir is built, and large quantities of loose rough stone are thrown in from time to time to fill up all gaps in the slope, until the whole work has become firm. Moreover, the sand in these rivers is of a coarser texture than that in Upper India, which, when saturated with water, becomes a mere quicksand, which would swallow up a much greater quantity of stone than the other. The weir, you will observe, is provided with sluices, by which the accumulated silt in front of the heads of the canals may be scoured through the body of the work, these sluice-heads for the supply of the canals on both banks of the river being built at the two ends of the weir. This system has generally been applied to the deltas of the Madras rivers, and the more gentle slope of the country has enabled these canals to be largely used for navigation as well, to the great advantage of the traffic; the fall of the bed is often only six inches per mile, or even less.

But besides its canals, Southern India, as well as Central and Western India, make enormous use of Tanks or reservoirs for the purpose of irrigation, the undulating and broken nature of the country as clearly indicating their use, as the flat plains of Northern India appear to demand canals. Many of these tanks have been in use for ages, and in the single province of Mysore alone there are not less than 30,000; hence, of course, they vary much in size, from those with an area of a few square yards up to those which contain several square miles, and which form artificial lakes on which you can navigate. The revenue of the country depends on the maintenance of these tanks, as in the case of canals elsewhere, and the chief duty of the Madras engineers is their inspection and repair, in concert with the civil officials of the district.

However much tanks may differ in locality and size, they may all be said to consist of the following parts:—1. A Dam or bund, natural or artificial, or both, by which the water is restrained. 2. A Stream, by which the tank is fed, unless it is fed by direct rainfall. 3. A Sluice or sluices, by which the ponded water is drawn off to be used for irrigation. 4. A Waste Weir, overfall, or Calingula, by which, when the tank is full, surplus water can escape safely. The Dam is generally the most important work in a tank, and the determination of its site, and the construction of it when chosen, often demand engineering skill of a high order. It is, of course, first of all necessary to take a very careful series of levels in order to determine whether the amount of water that can be ponded up by a given length and height of dam will be enough to pay for the cost of the work. Next, you must determine whether there is a sufficient area of land in the vicinity demanding water, and whether you are pretty sure of a good supply of water for the tank.

The Dam may be built of earth or stone, or of a combination of the two; and in the case where a great depth of water is ponded up, the foundations of the dam must, of course, be constructed in the most substantial and careful manner, for a failure may involve not merely the destruction of the tank, but the loss of hundreds of lives. The question of the best form of retaining wall to withstand the pressure of great depths of water, has excited a good deal of discussion, and you will find some of the best sections in the ‘Papers,’ as well as a good description and diagram of calculation of the Moota Dam in Bombay.

The other chief point in a tank besides the dam is the Waste Weir, which is generally built at the exit from the tank of the original channel by which it is fed. It must be made of sufficient length to discharge the maximum quantity of water which your calculations have shown you is likely to pass over it, and it must be strong enough, both in body and foundation, to resist both the pressure and the shock of this water. For this latter purpose, the principle of the vertical canal fall, already described, is often used, and the falling water is received into a cistern, by which its shock is broken.

You will find a chapter devoted to tanks in the ‘Roorkee Treatise,’ and several examples of the different kinds employed.

As to the irrigating duty of tank water, it is roughly calculated that a cubic yard of water is required for every square yard of land; this, however, refers to rice, which takes far more water than wheat. We have not time to pursue the subject further.

Before closing the subject of irrigation works, I may perhaps be allowed to name one or two of those engineers who have added most to our knowledge of that science. Foremost stands the name of the late Sir Proby Cautley, F.R.S., of the late Bengal Artillery, the designer and constructor of the Ganges Canal; then of Sir A. Cotton, of the Madras Engineers, his great rival, head and founder of the Madras school of irrigation; Colonel Baird Smith, F.R.S., chief engineer at the siege of Delhi; and then the late Colonel Dyas, of the Bengal Engineers, one of the most scientific officers in India.

Though not exactly under the head of irrigation works, the question of River Works, or river improvements, is not very far removed from it, and though we have but little time to spare for it, it would not be right to exclude such a subject altogether from your notice, for many of you will probably have a good deal to say to it sooner or later.

An engineer is generally called upon to devise works for the improvement of a river, either to increase its navigable facilities or to prevent its waters from inundating the country. With regard to the first object, the work in India generally consists in removing obstacles, such as shoals, kunkur banks, sunken trees or boats, and I cannot do better than draw your attention to the admirable paper on the Gogra River Works, sent to me by the late Lieutenant Carroll, R.E., whom I have already mentioned. The systematic improvement of rivers by the lock and dam method, as in the Thames and other small streams, is hardly applicable to such rivers as the Ganges and Indus, except at a cost which puts it altogether out of the question. It is greatly to be regretted that it is so, for the navigable capabilities of Indian rivers are far inferior to what we should suppose, judging from their length and size; much inferior to those of America, for example, though the Mississippi has much the same general characteristics as the Ganges.

During the rainy season, Inundations in the lower part of the course of many of these Indian rivers often extend far inland; the delta of the Ganges is, in fact, a vast sheet of water at that time of year, and in the dry season it is an enormous jungle intersected with watercourses, and inhabited only by tigers, snakes, and other wild animals, with the exception of a few wretched fishermen or woodcutters.

Higher up the country, again, rivers, such as the Damooda, are restrained within artificial embankments, which, unfortunately, have not been systematically planned, but have been erected from time to time by the different villages threatened with inundation along its course. There are often many miles of such embankment (or levees, as they are termed in America,) under a young engineer’s charge, and very anxious work it is, as he has to guard a long line from the attack of an insidious foe, often with a very imperfect garrison. Such embankments as these are always constructed of earth, and when consolidated by time and covered with grass, a very thin earthen bank will successfully resist until it is absolutely overtopped, while new earthwork of twice and three times the sectional area will be soaked through and breached readily. Another source of danger arises from rats and other vermin, which perforate your embankments in hundreds of places.

Rivers are also trained, either to prevent inundations or to improve their navigation, by the use of Spurs or groins, which are much employed in India. They are generally run out from the shore at an angle of 45° with the current, so as to deflect it towards the opposite side when needful. By a series of such spurs, a long line of bank may be protected, and a corresponding series on the opposite side may often be necessary to give the stream a set in the right direction. Such spurs may be built of stone where there is any, but in India are more often constructed of a double row of piling, filled in with fascines; the nose of the spur is often revetted with sand-bags. Sometimes ropes are anchored, and trees or brushwood tied along the rope, by which the surface current is acted upon sufficiently for the purpose. In the Markunda River, near Umballa, well-cylinders were sunk down at a great expense, to act as anchors, and were connected by stout iron chains or wire cables, to which trees and branches were attached. The advantage of spurs founded on the bottom over floating spurs or breakwaters is chiefly in the great deposits of silt which occur both above and below the latter, and which soon form an adequate protection to them from the stream.

For all this kind of work it is impossible to lay down any fixed rules; experience and local knowledge are our chief guides, though it may be said generally that rivers are like women—more easily led than driven!

I have now run over—very hastily and imperfectly, it is true—the chief branches of civil engineering which those going to India may be called upon to engage in. There are several other important branches, such as Lighthouses, Harbour works, Gas, Water, and Sewage works, on which I have not touched, both because you will rarely have anything to do with them, and because there is very little that is special about them so far as India is concerned. But before I conclude, I wish to give you a brief account of the Indian Survey, partly because the results of that survey are of great importance to the engineer, and because many of our own officers are employed in it.

The Indian Survey Department is divided into the three branches of the Great Trigonometrical, the Topographical, and the Revenue, Survey branches. To understand something of the work done by the first, it is necessary to sketch briefly the history of its operations. It was in the year 1800 that Major Lambton commenced to run a line of triangles across India from Madras to the west coast, with a view simply to a local survey. In the course of this work it was discovered that there was an error of no less than 40 miles in the assumed breadth of the peninsula at that point. The original Base Line was measured near Madras, and a base of verification at Bangalore, and from this latter base a line of triangles was subsequently carried down south to Cape Comorin, and up north to Dera, 40 miles from Roorkee. This line, carried along the centre of the continent, formed the Great Indian Arc, and is the largest arc of longitude ever yet measured on the earth’s surface. Another great line of triangles has since been carried from Kurrachee, in the west, to Calcutta, in the east, bases being measured at each end. From Kurrachee, again, the Indus series of triangles extends to Attock, where another base was measured, and from Attock another chain comes down the Punjab back to Dera. There are several other series of triangles with which I need not trouble you.

In the earlier days of the survey, the instruments used, especially those for base measurement, were necessarily imperfect, but Colonel Colby’s compensation apparatus, used in the Irish Ordnance survey, was afterwards sent out to India, and two 36-inch theodolites, made by Troughton and Simms, which, I believe, are the very best instruments ever turned out. Subsequently, several 24-inch theodolites on the Everest pattern were sent out, besides a first-rate Zenith Sector, and many other instruments; and all the old work has been re-measured, while fresh series of triangles are yearly being added. The published results of the work show that it is singularly accurate, and may bear comparison, in this respect, with our own or the Russian survey, while in the magnitude of its operations it surpasses both. I should mention that for the principal triangulation stations in the plains, high towers of masonry are built, from which the angles are taken. The stations on the peaks of hills are marked by small pillars of stone.

Besides the ordinary triangulation, and the determination of the Latitudes and Longitudes of the chief stations by careful Astronomical observations, a series of very valuable Pendulum observations has been lately executed for the Royal Society at intervals along the Great Arc, the object being to determine the effects of local attraction on the plumb-line caused by the great mountain chain of the Himalayahs. It was while engaged in these that Major Basevi, Royal Engineers, died alone in the solitudes of Thibet.

In addition to the above, a very extensive series of Spirit-Levelling operations has been undertaken within the last few years by the Survey Department, the object of which is to have an independent mode of determining the height of the principal stations in the interior above the mean sea-level at Kurrachee, and to establish a series of Bench Marks all over the country, by which the levels taken for any engineering project may be referred to the Kurrachee datum.

Major Lambton was succeeded by the late Sir George Everest and Sir Andrew Scott Waugh, F.R.S., now retired, both of the late Bengal Engineers. The present Superintendent of the Great Trigonometrical Survey is Colonel J. T. Walker, F.R.S., late of the Bombay Engineers, who some years ago executed an admirable military survey of the Trans-Indus frontier under circumstances of great difficulty and peril. His second in command is Major Montgomerie, F.R.S., late Bengal Engineers, who received a gold medal from the Royal Geographical Society for his admirable survey of the kingdom of Cashmere, one of the completest and most difficult surveys ever executed. Among the other subordinates is Lieutenant Herschel, F.R.S., late Bengal Engineers, a son of the great astronomer, and already well known to the scientific world for his spectroscopic observations on the last two total eclipses of the sun.

The Topographical Survey is confined to those large tracts of country which, from their hilly and jungly configuration, would not pay to be surveyed in the elaborate manner employed in the plains. The instruments used for the triangulation are 7-inch Everest theodolites, the stations being always connected with the most convenient points of the Great Trigonometrical Survey. The details of the country are filled in by the Plane Table, which is similar to the sketch block, and though not so portable, is more convenient and perhaps admits of greater accuracy. Many very beautiful maps have been turned out by this Department, the head of which for some years was Colonel Robinson, late Bengal Engineers, one of the most accomplished military draughtsmen in the service, now Director-General of the Indian Telegraph Department.

The Revenue Survey is, as its name denotes, the survey of land for the purpose of revenue assessment. It takes up the chief points determined by the Great Trigonometrical Survey, runs secondary lines of triangles where necessary, and fills in details by the Gale Traverse system, which is specially adapted to a flat, open country. The Plane Table supplements the Traverse work, and the result is a series of maps which, for minute detail, are scarcely equalled by the 25-inch English Ordnance maps, for every field is determined and even the nature of the soil and the crop laid down.

The Revenue Survey is presided over by the Surveyor-General of India, Colonel Thuillier, F.R.S., late Bengal Artillery, who has for many years devoted himself specially to this work, and to whom India is indebted for many improvements.

And now, Gentlemen, I have finished my lectures, and would fain hope that they have given you half as much pleasure in listening to them as I have had in preparing them. The field was so vast that I could easily have extended their length and their number; but my object has been rather to awaken your interest and stimulate your curiosity than to supersede your reading.

FOOTNOTES:

LONDON: PRINTED BY W. CLOWES AND SONS, STAMFORD STREET AND CHARING CROSS