Virginia City Water-Works.—The
Virginia and Gold Hill Water Company have an inverted siphon across the
Washoe Valley, Nevada, 7 miles long, 11-1/2 inches in diameter, of
riveted wrought iron. The total weight of the siphon is about 700 tons.
The pipes were hot-riveted, with a single row on the circular and a
double row on the longitudinal seams, a million rivets being used. The
separate lengths were united by lead joints, previously described (see
p. 163). For these 35 tons of lead were required. The pipe was
constructed in 1872 of inferior English iron, but is still (1883) in
good condition. The No. 9 iron is strained fully 15,000 lbs., and the
No. 7 over 14,006 lbs., per sectional inch. The pipe is said to have
been tested to a pressure of 1,400 lbs. per square inch.
The
annexed sketch (Fig. 27) shows the profile. The numbers along the line
give the thickness of iron, B. G., used under the various pressures
which are indicated in the perpendicular columns of figures from 100 to
1,700 (feet), at the points where the parallel lines strike the
profile. The triangles below the line denote the locations of the
blow-offs, and 0, above the line, represents the air-valves. These have
been previously described (see pp. 166, 167).
Spring Valley and Cherokee Hydraulic Mining Company.—At
Cherokee, Butte County, California, the Spring Valley and Cherokee H.
M. Company has an inverted siphon of wrought iron, 30 inches in
diameter, which discharges 53 cubic feet of water per second. This was
the first large construction of the and on the coast. It has been in
continuous use for 12 years, and is still in good condition. The
material was ordinary English plate. The greatest pressure is 887 feet.
The sketch * (taken from the original survey) shows the profile and the different sizes of iron used. The maxi-
* The Mining and Scientific Press of January 7, 1871, contains a detailed account of the construction of this pipe and a diagram of the line.
