The soil in which the four service reservoirs on the railway are built proved to be about the worst for such work. In its natural state on the prairie, after the excavation for the reservoir was completed, it filtered water at the rate of 3 ft. per day. Tamping and puddling still left a filtration of 12 in. per day, with a tendency to increase. Enough water filtered through the concrete to produce settlement and cracks. Finally, the concrete was water-proofed with two coats of soap, two of alum, and one of asphalt. This has made all the reservoirs water-tight. Elaterite, an asphalt paint made by the Elaterite Paint and Manufacturing Company, of Des Moines, Iowa, was used successfully on the Luna Reservoir. This paint is applied cold, and preliminary tests showed it to be quite efficient. The analysis of the soil is as follows: Loss on ignition 3.35 Silica 56.36 Oxide of iron 2.93 Oxide of aluminum 8.97 Calcium oxide 15.95 Magnesium oxide 0.98 Oxides of sodium and potassium 0.47 Carbonic acid 11.35 Sulphuric acid 0.11 Chlorine 0.04 Manganese Traces ------ 100.51 Insoluble matter, 64.50 per cent. _Pipe-Line Leakage_.--There is no measurable leakage from the iron pipe. By thorough inspection and measurement at the end of two years, leakage on the wood pipe, between Coyote and Bonito Creek, from the 11-and 12-in. pipe, was found to be as follows: On 8.6 miles, 11-in. pipe, 146,600 gal. per day = 17,046 gal. per mile. " 4 " 12 " " 14,829 " " " = 3,702 " " " The 7-1/2-in. pipe on this section appears to be leaking less than the 12-in. pipe. Inspection and measurement of it are to be made in a short time. There is no material leakage from the 10-and 16-in. pipe between Bonito Creek and Nogal Reservoir, as determined by velocity and volumetric measurements hereafter described. The greatest probable error in the velocity measurements would not exceed 1/2 per cent. If such error existed, and was all charged to leakage, it would amount to but 17,204 gal. per day, or 1,582 gal. per mile, out of a daily delivery of 3,784,000 gal.; but the measured discharge of the pipe, as determined by the velocity, was 5.84 sec-ft., while the mean maximum volume of this water over the weir at the end of the pipe is recorded by the weir as 5.88 sec-ft. From Coyote, east along the railway, the wood pipe is remarkably tight. The rate of leakage from it, as determined by 600 observations uniformly distributed, was as follows: 11-in. pipe = 120 gal. per mile per day. 8-1/2 and 7-1/2-in. pipe = 268 " " " " " The maximum rate on 1 mile was 1,613 gal. The minimum found was zero.