Chapter IV: Part 4

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:

[A] I remember a native’s answer to a remark of mine, which shows that there are always two sides to a question, even a question of improvement. His Persian wheel, near to which my tent had been pitched, kept me awake all night with its abominable creaking, and I asked him in the morning why he didn’t use grease to stop the noise? He said, “I am accustomed to it, and if the creaking ceases I wake up; I know the wheel has stopped because the bullock-driver has gone to sleep, and I go out and beat him.”

[B] The Grand Trunk Road having been first metalled with kunkur when Lord William Bentinck was Governor-General, that distinguished nobleman was called by some facetious engineer, William the Kunkurer.

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_A Practical Treatise on Concrete, and how to Make it._ With
Observations on the Uses of Cements, Limes, and Mortars. By HENRY
REID, C.E.

Third Edition, royal 32mo, roan, 4_s._ 6_d._

_A Pocket-Book of Practical Rules for the proportions of Modern
Engines and Boilers for Land and Marine purposes._ By N. P. BURGH.

Details of High-pressure Engine, Beam Engine, Condensing, Marine Screw Engines, Oscillating Engines, Valves, &c., Land and Marine Boilers, Proportions of Engines produced by the rules, Proportions of Boilers, &c.

* * * * *

Just published, 2 vols. medium 8vo, cloth, illustrated by a Steel
Portrait, Lithographs, and numerous Wood Engravings, including many
accurate Illustrations of Cornwall, its Mines and Mining Machinery,
£1 16_s._

_The Life of Richard Trevithick, Inventor of the High-pressure Steam
Engine._ By FRANCIS TREVITHICK, C.E.

Crown 8vo, cloth, 1_s._

_How to Publish a Book_;

Being Directions and Hints to Authors. By ERNEST SPON.

Just published, in crown 4to, cloth, with Wood Engravings, 25_s._

_A Treatise on the Construction and Operation of Wood-working
Machines_, including a History of the Origin and Progress and
Manufacture of Wood-working Machinery. By J. RICHARDS, M.E.

Just published, 4to, cloth, 25_s._

_Picturesque Architectural Studies and Practical Designs for Gate
Lodges, Cottages, Cottage Hospitals, Villas, Vicarages, Country
Residences, Schools, Village Churches, etc., etc._ By W. YOUNG.

Just published, 8vo, with Plates, 5_s._

_On the Construction of Catch-water Reservoirs in Mountain Districts,
for the Supply of Towns, or for other Purposes._ By C. H. BELOE,
Author of the ‘Handbook of the Liverpool Waterworks.’

Just published, 8vo, cloth, Illustrated with Coloured Plates, 16_s._

_Vazeeri Rupi, the Silver Country of the Vazeers, in Kulu: its
Beauties, Antiquities, and Silver Mines, including a Trip over the
lower Himalayah range and Glaciers._ By J. CALVERT, F.G.S., Mem.
Inst. C.E.

London: E. & F. N. SPON, 48, Charing Cross.
New York: 446, Broome Street.