in. deep and remaining distinct under the water around the shore line
for one year. Apparently, the reservoir will finally become water-tight
at all elevations.

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