Where sunk tanks are already constructed, they may be rendered more available by a partial use of the method shown in Fig. 6.
Memoranda of Experiments tried on the mains and service pipes of the Southwark Water Company, between 4 and 9 A.M. of the 31st January, 1844. The wind blowing fresh from N.N.W.
The pressure at the water-works at Battersea was kept at 120 feet during the experiments, and every service pipe or other outlet was kept shut.
1st Experiment.—Six standcocks, with one length of 2-1/2 inches riveted leather hose 40 feet long, and one copper branch 4 feet to 5 feet long, with a jet 7/8 inch in diameter on each, were placed in six plugs on a main 7 inches diameter, in Union-street, between High-Street, Borough, and Gravel-lane, Southwark, at distances of about 120 yards apart. The water was brought from the head at Battersea, by 4250 yards of iron pipes 20 inches diameter, 550 yards of 15 inches diameter, and 500 yards of 9 inches diameter.
1st. One standcock was opened, which gave a jet of 50 feet in height, and delivered 100 gallons per minute.
With four lengths of hose the jet was 40 feet high, and the delivery 92 gallons per minute. When the branch and jet were taken off with one length of hose the delivery was 260 gallons per minute.
2nd. The second standcock was then opened, and the jet from the first was 45 feet high.
3rd. The third standcock was opened, and the jet from the first 40 feet high.
4th. The fourth standcock being opened, the first gave a jet of 35 feet high.
5th. The fifth being opened, the first gave a jet of 30 feet high.