456
32. Allowing 15 gallons a head per diem for the barracks we get as the present requirements throughout the districts mentioned in section 20 147,000 gallons per diem.
33. According to the last Census of 1891 the total Land Population of British Kowloon was 19,997 and the Boat Population 6,447, making a total of 26,444. Comparing these figures with those obtained at the Census of 1881 the increase during the last decade has been at the rate of 96 per cent.
34. It would appear scarcely probable that this rate of increase can be maintained when it is remembered that the increase of population in this Colony is mainly due to immigration, the annual returns of births and deaths shewing that the rate per cent, of the former are about one-third that of the latter. There is, however, no apparent reason why a material increase during the next 10 years should not be anticipated, and I am of opinion, though the immediate requirements of the population do not render it necessary, that works should be constructed for the supply of more than 150,000 gallons per diem; yet such works as are constructed should be so arranged as to admit of their being extended to meet the requirements of a population of 50,000, or say, the supply of 500,000 gallons per diem.
PROPOSED PROJECT.
35. After carefully considering the foregoing facts, I am of opinion that the best project for obtaining a reasonable public water supply for British Kowloon to meet its present requirements and provide for extension if necessary is-
(a) The reservation of the four valleys, numbers 1, 2, 3 and 4 on the plan, for water works
purposes.
(b) The sinking of wells in valleys numbers 2 and 3 and laying subsoil drains as in the case of valley number 1 already described, which will, I anticipate, as stated in section 26, furnish a minimum supply of 232,000 gallons per diem.
(c) The collection of these waters by means of cast iron pipes laid with water-tight joints through the cultivated lands in valley 4. I propose that owing to the wet nature of the soil in order to avoid pumping in the trenches and in consideration of the small pressure to which they will be subjected, that the joints of these pipes should be made with iron filings and Šal Ammoniac; this course will dispense with the use of lead which under the circumstances would be liable to be picked out and stolen.
(d) The erection of Pumping Machinery at the north end of Yaumati for the purpose of pumping water to a reservoir to be constructed on the hill at an elevation of about 230 feet above Ordnance Datum.
(e) The distribution of water by means of cast iron pipes jointed with lead throughout the built area of Mongkoktsui, Yaumati, Tsimshatsui and Hunghom. The principal mains being laid of sufficient size to admit of their ultimate extension to the remaining portion of British Kowloon.
DESCRIPTION OF WORKS REQUIRED.
36. The wells to be sunk in valleys numbers 2 and 3 to be nine feet (9'. 0") internal diameter built on an iron curb and sunk till the impervious substratum is reached, a short distance below each well a concrete dam should be constructed founded on the impervious stratum and carried up to ground level to prevent the natural flow of the waters of the valleys to the sea.
37. The cast iron main laid down the valley from well number 2 to commence in a pipe six inches (6") in diameter increasing in size as it receives the water from well number 3 to 7 inches in diameter terminating at the Pumping Station in the suction pipe of the pumps. The branches from wells numbers 1 and 3 being six inches in diameter.
38. In the Pumping Station it will be well to install pumping machinery in duplicate capable of lifting 200,000 gallons per 24 hours to a height of 275 feet giving a combined effective Pump Horse Power of 24. If steam is used the engines might be of the Worthington type triple expansion. No water is available for a jet condenser and in view of the water in the harbour being some 400 feet away from the proposed site of the Pumping Station unless supplementary pumping machinery is provided I do not think much advantage would be gained by using a condensing type of engine. A Hot Well should be provided into which the exhaust steam should be conveyed and from which the water for the supply of the boilers should be pumped by a donkey pump. The boilers should be of the Cornish or Lancashire type fitted with Galloway tubes, this type being more accessible for inspection and easier of maintenance than any of the multitubular types, working pressure 80 lbs. Before, however, deciding to adopt steam as the motive power it would be well to enquire into the first cost and subsequent cost of maintenance and working of petroleum engines which have of late years, I believe, come into very general use. It is not at all improbable from the power required, viz.: about 12 Horse Power that an engine of this type will be found most suitable,