instead of being spread in irregular cracks all over the reservoir, the leaks were confined to the lines on which the above-mentioned joints occurred: they were easily located, and were effectually stopped by cutting out portions of the joints to a depth of 2 or 3 inches, caulking with oakum, and facing with bitumen and tar. Reticulation. The original scheme did not allow for any reticulation of townships for domestic purposes, or of miningcentres, it being only intended to bring the water to some high hill -for instance, Mount Burgess a few miles north of Coolgardie -and to lay a subsidiary main thence to such situation in each township or mining-centre as the local authority should choose for its service-reservoir. Eventually, however, the complete reticulation of the townships of Kalgoorlie, Coolgardie, Boulder, and the Kalgoorlie Mining Belt, had to be undertaken as part of the main scheme, in addition to the laying of small pipes to mining-centres near Coolgardie and Kalgoorlie; but one or two of the smaller townships, namely, Northam and Southern Cross, have installed their own reticulation, purchasing water in bulk from the main scheme, and retailing it to the ratepayers. A separate telephone-line for the works was laid down between the head office at Perth and Kalgoorlie. It is of ordinary type, with one repeating-station about half-way, and was extremely useful during construction. Connection is thus secured between the head office and the pumping-stations, and, by means of fieldtelephones, with the maintenance-gangers. VI.-COST OF THE WORKS. The actual cost, including all extras, contingencies, and establishment charges, was £2,660,000, an excess of £225,000, or 91 per cent., on the original estimate, after deducting from the latter £65,000 for works which were allowed for therein but were not carried out. This can hardly be considered a large excess when it is remembered that the original estimate was based on tentative data prior to survey; but as a matter of fact almost the whole of the excess is accounted for by one item alone, namely, pumping-plant, partly due to somewhat more water having to be pumped, partly to the provision of more reserve power for accidents, and largely to enhanced cost per horse-power. Low-duty engines were originally allowed for at an estimated cost of £22 per horsepower, while the actual cost of the plant installed was nearly £48 per horse-power, including Federal customs duty, spares, etc. So long as the consumption of water remains much below the ultimate amount allowed for, and so long as cheap local fuel (firewood) remains available, the high-duty plant will not prove as economical as the low-duty and cheaper plant would have been; but the conditions will be different when the full consumption is reached, and utilization of the more costly fuel becomes necessary. The total expenditure of £2,660,000 was sub-divided as follows: Storage-reservoir, including 5 miles of railway-line, land-compen sation and river-training works (capacity of reservoir being Service- and break-pressure reservoirs of a total capacity of Telephone-line and other contingencies £ 280,000 60,000 1,870,000 290,000 140,000 20,60) £2,660,000 On the death of Mr. O'Connor, in March, 1902, the Author succeeded him as Chief Engineer, when about one-half of the works had been constructed. The progress was largely governed by the necessity for testing the long lengths of main between the various pumping-stations as soon as possible, and also by the rate at which the valves and specials could be obtained from England. In conclusion the Author wishes to express his obligation to Mr. William Coates Reynoldson for much assistance rendered. Mr. Reynoldson was the Author's principal assistant on the scheme, and is now in charge of the works as Engineer to the Trust which was constituted by an act of the West Australian Parliament for maintenance and management of the works. The Paper is accompanied by ninety-one sheets of drawings, from which the illustrations in Plates 1, 2 and 3, and in the text, have been prepared; also by an Appendix from which the following Tables have been selected for publication. [APPENI IX. APPENDIX. TABLE I.-DISCHARGES OF CATCHMENT-BASIN OF HELENA RIVER and of * Reservoir overflowed 9 September, 1898, and 28 July, 1900, and the water that went to waste is not included in the above figures. TABLE II.-DISCHARGE OF STREAMS ENtering MunDARING RESERVOIR 1 JANUARY, 1903, TO 16 August, 1903. TABLE III-RAINFALL AT PERTH GARDENS, MUNDARING AND YORK. TABLE IV.-EVAPORATION AT PERTH OBSERVATORY, AND AT NOTE.-The figures in column 2 were furnished by the Government Astronomer as being the lo ss per diem in Perth. The total of figures in column 3 for the 4 months from 1 November, 1901, to 28 February, 1902, was obtained by observation at Mundaring Weir as 2 feet 6 inches, and the figures for each month, shown in columns 3 and 4, were calculated therefrom at the proportion obtained from column 2. |