sanitary scheme which shall serve as model and example to other municipal bodies undertaking the same responsibility; and to such a Corporation and to such men do I, likewise, your Officer of Health, respectfully and confidently address a well-founded appeal.

I have the honour,

&c., &c.

FURTHER REMARKS ON WATER-SUPPLY.

ADDRESSED TO THE HEALTH-COMMITTEE OF THE HON. THE COMMISSIONERS OF

SEWERS OF THE CITY OF LONDON, PURSUANT TO A REFERENCE—

"What would be a sufficient supply of water to the houses and premises within the City, and the best principle upon which to effect such supply?"

February 21, 1850.

GENTLEMEN,

Such further observations on the subject of ' Water-Supply to the City' as you have desired me to lay before you, I have now the honor to submit, in as condensed a form as possible.

First, I may remind you, that in my report of last November, which still remains under your consideration, I stated the following ' as the chief conditions in respect of Water-Supply, which peremptorily require to be fulfilled.

1. That every house should be separately supplied with water ; and that, where the house is a lodging-house, or where the several floors are let as separate tenements, the supply of water should extend to each inhabited floor.

2. That every privy should have a supply of water, applicable as often as it may be required, and sufficient in volume to effect at each application a thorough flushing and purification of the dischargepipe of the privy.

3. That in every court, at the point remotest from the sewergrating, there should be a stand-cock for the cleansing of the court; and

4. That at all these points there should always and uninterruptedly be a sufficiency of water to fulfil all reasonable requirements of the population.'

In re-organising the system of water-supply there are some other purposes, of a more public nature than these, which would likewise claim your attention: such as (1) an improved arrangement for meet

ing all accidents and emergencies of fire; (2) an efficient distribution of water to all common urinals and privies; (3) a sufficiency of supply for any public baths and wash-houses, which may be hereafter erected; and (4) an ample surplus to be at the disposal of the Commission for the cleansing of streets and sewers.

In order that those domestic purposes, which I first enumerated, should be adequately fulfilled, the supply of water ought, practically speaking, to be without limit to any individual consumer. It is the tendency of the system of constant supply, and constitutes a distinguishing advantage of that system, that it fulfils this important condition without any increase, or perhaps rather with a diminution, of the total draught of water for a large population.

The average of requirement (estimated from the consumption of large communities) would probably be about 12 gallons per person per diem; making an amount, for the total population of the City, of about 1 million gallons per diem. Assuming this estimate to be correct, a point which I would beg you to observe is the following: that, although there might be very little fluctuation in the total quantity consumed, and although it might remain constant at the figure I have given, yet in the items of individual consumption, making up this gross amount, there would be almost infinite varieties. One family would habitually consume twice as much water as another family of the same size: one family would consume six gallons per person on five days of the week, and would require all its remaining quota on the other two days; and so forth. These differences and caprices of individual requirement do not sensibly affect the total quantity consumed in a given week by a population of 130,000 persons; one consuming more, another less, the first counterbalances the last in forming the materials for a fair personal average; and a source of supply calculated from such an average for a large population would, practically speaking, be unlimited to each individual consumer, provided only that it were so distributed, that each consumer could draw from the common stock at his own time and according to his own necessity. This advantage is obviously lost under the present system of intermittent supply, which compels a larger total distribution than would else be requisite, entails the expensive and unwholesome necessity for storage, and yet is notoriously fraught with the inconveniences of a restricted source, or a defective supply.

I have no sufficient data for judging with precision what quantity of water might be required to fulfil all those public purposes of cleanliness and of protection from fire, to which I have adverted. The supply would require to be practically inexhaustible; but the consumption, on an average of the four seasons, would probably lie considerably within half a million of gallons per diem.

When the distribution of water is brought into its proper relations with the drainage of the City-that is, when the arrangements of domestic drainage are completed, in conformity with the intentions of the Act of Parliament, and when all the water, distributed for private consumption, is made to traverse and to cleanse all the channels of house-drainage, it is probable that a smaller quantity of water than is now consumed will suffice for the flushing of sewers, and for other so-called sanitary purposes.

The quantity at present supplied to the City by its two WaterCompanies is perhaps much in excess of the two millions of gallons per diem, which I have estimated as a sufficiency for our population; but the distribution is so unequal, and the waste of the intermittent system so incalculably great, that the effect produced on the population is, to a very great extent, that of scarcity.

With regard to the principle of supply on which I have been. desired to report, it seems certain to my mind, from such evidence as I can collect on the subject, that the system of continuous supply at high-pressure promises advantages which can never be realized under the present system of intermittent supply. There are many matters connected with the comparison of these two systems, which lie beyond my sphere of professional observation, and on which I would not be bold enough to offer any opinion to your Committee. The sanitary points, on which alone I would venture to insist, as benefits in the system of continuous supply, are-first, the practical inexhaustibility of the source, and secondly, the absence of necessity for storage. If these benefits are attainable, and especially if (as alleged) they can be obtained at a material economy of expenditure, as compared with the present system, there can be little doubt as to which should obtain the preference.

If your Committee should wish, it would be easy to prepare for your examination a digested summary of such scientific evidence as has been given on these points: or it might be expedient, if such a course would be more satisfactory to you, that some person in your confidence should undertake to visit and inspect one or more of the

towns where the system of continuous supply is in operation, and where direct information can be gathered on the very important particulars of its practical efficiency and success. But, at all events, whether your Committee should wish or should not wish this personal investigation to be undertaken, I would suggest, that it might be satisfactory to you and serviceable to the inquiry in which you are engaged, if you would procure a report from some eminent hydraulic engineer, practically conversant with the system of continuous supply, who might furnish you with conclusive testimony as to the admissibility of this system within the City, and as to the advantages and disadvantages, sanitary and economical, which might attend its adoption here, as compared with that which has hitherto prevailed.

It appears to me that at the present time the system of continuous supply might, provisionally, receive a fair trial in the City, in respect of some of those poorer habitations, which are now for the first time about to be supplied with water and drainage. The Water-Companies would probably not object, if desired by the Commission, to supply a hundred houses, experimentally, with constant pressure from their mains. The Commission might select for its experiment some of those courts about Cripplegate or Bishopsgate, where the drainage, as well as the water-supply, requires to be constructed anew: some, where there have hitherto been undrained cesspools, and where the water-supply has been from a stand-cock. Should this suggestion be found feasible, I would recommend that the details of its execution should be carried out under the joint superintendence of your Surveyor and myself, and that we should afterwards report to you its results, as material for guiding your decision with regard to the general supply of the City.

Mr. Quick, Engineer to the Southwark Water-Works, in a letter which is appended to Sir William Clay's pamphlet, has recently suggested various arrangements for an uninterrupted supply, and these have no doubt been under your Surveyor's consideration. I may add, too, that there are at present upwards of 40 houses within the City constantly supplied from the mains of the East London WaterWorks; but as these are not houses of the poorest description, it is possible that they may not constitute so satisfactory a proof of the feasibility of the constant supply, or so complete an illustration of the detailed arrangements for its employment, as could be given by the experimental construction I have suggested.