character-1st, The supply of water would be cool and fresh, and free from the pollutions which are unavoidable in the ordinary system; 2d, Waste would be reduced nearly to a minimum; and, 3d, The poisonous air from the drains would no longer be conveyed into the house through the waste-pipe.

The benefits to be derived from the attainment of the first and third of these items appear sufficiently plain; but in regard to the second, it does not seem to have obtained that amount of consideration in the eyes of the general public which its importance deserves. I venture, therefore, to bring this matter again prominently before you, notwithstanding my full sense of the hazard of being accused of telling a twice-told tale.

I

In the paper I had the honour to read to the Society on 23d November last, I referred to certain experiments I had made to ascertain the discharge of water through minute orifices, with a view to illustrate this question of waste. refer to the large table I have placed upon the wall for the particulars of these experiments. You will observe in the first column of that table that the diameter of the orifice is there stated in decimals of an inch; in the second column, you have the pressure in vertical feet; and in the third, the discharge of water through these orifices respectively in twenty-four hours. I again submit the discs containing the orifices to your inspection, and on the present occasion I ask your attention only to three of them—namely, to one marked '05, or 5-100th parts of an inch; the second marked 25, or one quarter of an inch; and to that marked 40, being 4-10ths of an inch.

The first of these, you will observe, is so minute as scarcely to admit a small needle. Be so good, however, as to observe the quantity of water which, with a pressure of only 150 feet, will pass through it in twenty-four hours. Minute as the orifice is, you will find that it is no less than 613 gallons-a quantity sufficient for the supply of thirty persons, with the not illiberal allowance of 20-43, say 20 gallons per head for the twenty-four hours.

In the disc marked 25, with an orifice of one quarter of

an inch, you will find on referring to the table, that with a pressure of 143 feet it will discharge in twenty-four hours 13,416 gallons. But I refer you more particularly to the disc marked 40, with an orifice of four-tenths of an inch. You will find, on again referring to the table, that with a pressure of only 120 feet the discharge amounts to the astounding quantity of 34,285 gallons in twenty-four hours. I have referred you to the first two of these as representing the respective quantities that may be run off merely by leaks equal in capacity to these respective orifices. The disc, with an orifice of four-tenths of an inch, I bring before you as representing the discharge from a ball-cock of a capacity equal to the four-tenths of an inch of the disc; and in doing so, I have to remind you that very few, if any, ballcocks in use here are of so small a capacity as four-tenths of an inch. The common sizes are half-inch, five-eighths, and three-quarters of an inch. Confining my remarks, however, to that of four-tenths of an inch, you will observe that if the ball governing a cock of that capacity remained down for twenty-four hours, and with a pressure of only 120 feet, no less than 34,285 gallons of water would be wasted. With ball-cocks of a larger capacity, the waste will be proportionately greater, but even with the smaller one, equal to the four-tenths of an inch of the orifice in the disc, the waste is equal to a supply of water to 1714 persons at the rate of twenty gallons per head; and taking the average size of ball-cocks, the waste from one alone would, under like circumstances, furnish twenty gallons per head to from 2000 to 3000 persons.

Now, taking all circumstances into account, I think it is not unreasonable to ask, whether that waste is the best, or, even a proper use to be made of the water? Is there no purpose to which it can be beneficially as regards the consumers, or profitably as regards the general public, applied? I venture to think that there are many such purposes, and that its application to these purposes would benefit the consumers and the general community in a variety of ways.

Edinburgh has never been remarkable as a place of trade or manufacture. It has been for many years, however, a

distinguished seat of printing, and some other branches of trade, which, although requiring a constant and steady supply of water, are yet independent of those large supplies usually derived from rivers or such-like sources, and I have the assurance of a gentleman at the head of one of the largest printing and publishing establishments in the kingdom, that, but for the steady and constant supply of water he receives from the Edinburgh Water Company, he would remove his establishment to London. That there are many others in a similar condition cannot be doubted; and I mention the circumstance in order to show that the surplus of the water not required for domestic and other preferential purposes, not only can be advantageously sold, but that when sold, would, by supplying steam-engines, and in numberless other purposes, contribute a large portion of the means of employment to the working population. It would be a waste of words to dilate on the advantages which would thus flow from sources of industry already established, or which may yet be opened up, or on the wholesome effect of abundant industrial employment. Of the latter, indeed, it may truly be said, and even more emphatically than of charity, that it is twice blessed.

But this question as to the sale of water addresses itself yet more directly to the interests of the inhabitants. The supply at command is the joint property of the whole community, and the primary and preferable pecuniary interests of the Water Company stop at the point where the dividend of 6 per cent., to which they are restricted, has been attained; and the surplus funds, after satisfying that dividend, become the property of the community, under the special provisions of an Act of Parliament; and are available for the reduction of the water-rates.

I have stated in my previous paper that, when the works authorised by the Act of Parliament of last session are completed, the total quantity of water in the Company's possession for the use of Edinburgh, Leith, and Portobello, may be held to be 900 cubic feet per minute, and that if that quantity were distributed over the present population— estimated at 208,647-it would afford a daily supply of 38.8,

say thirty-nine gallons per head; and if the supply were confined to twenty gallons per head per day, the surplus, valued at only 40s. per 100,000 gallons, would represent a sum of more than £21,000.

If by the use of proper house apparatus, and the avoidance of waste, even a fourth part of that quantity were set free for trade and manufacturing purposes, it would speedily realise a sum of money sufficient to effect an important reduction in the water-rates. It is needless to speculate as to what that sum of money may be. That it might be five, ten, or twelve thousand pounds, or even a larger sum, is a matter very much in the power of the inhabitants themselves; and as they would be the exclusive gainers, they should lend a willing aid in preventing the waste of an article which admits of a ready sale for their behoof. No one asks that for personal or household purposes it should be used in any stinted manner; but the exercise of even a very moderate degree of economy would be the means of promoting many branches of trade and manufacture, while the money derived from its sale would effect a reduction in the water-rate greater or smaller according to the extent of the economy the inhabitants might think fit to exercise.

I have thus endeavoured to show, that by a simple mechanical arrangement the water required for drinking, cooking, and similar domestic uses may, as a general rule, be drawn from the street mains fresh, pure, and cold; that the present immense waste of water is to a large extent preventible; that the noxious gases generated in the street and house drains may be excluded from the cistern and house; and that by the observance of even a moderate degree of economy in the use of the water, and by the sale of the surplus which would remain after satisfying those purposes which have a statutory preference, a large sum may be raised, which under the provisions of the Act of Parliament would fall to be applied to the reduction of the water-rates.

On the Wet Dock, and other works about to be constructed by the Commissioners for the Harbour and Docks of Leith. By GEORGE ROBERTSON, M. Inst. C.E., F.R.S.E.*

The prosperity of the port of Leith is so closely connected with that of Edinburgh, that I am induced to believe a short account of the extensive works, about to be undertaken by the Commissioners for the Harbour and Docks, may not prove uninteresting to the Fellows of this Society. During the next four years they will have so many opportunities of watching the progress of the dock, that it will give additional interest to their visits if they know beforehand what is about to be undertaken.

On looking back at a paper I read to the Society in September 1861—entitled "A description of the Reclamation Embankment for the New Dry Dock at Leith," I find stated, that one of the reasons which induced me to give that description, was a belief in the great importance to the inhabitants of Leith of a step which reclaimed for useful pur poses even six acres of the large tract of sands lying unemployed in front of a town which suffers from narrow streets and crowded dock accommodation.

Although it required no great spirit of prophecy to foresee that such a state of matters could not much longer exist, I certainly did not anticipate that, before that time next year, the plans would be definitely settled for giving life, energy, and value to the east sands of Leith.

During the last few years, the great increase in the import of corn, as well as the general prosperity of the trade of the port, more especially as carried on by steamers arriving and sailing at fixed periods, have taxed to the utmost its dock accommodation. The increasing size and draught of vessels require also a greater length of quayage in deep water than the limited size of the Victoria Dock affords. When such a

* Read before the Society on 11th January 1864, and awarded the Society's Silver Medal.