VARIOUS MECHANICAL APPLIANCES. 191
Grass
Valley, with the Fredenburr, Pelton, Knight, and Taylor wheels, the
results of which are given below. The tests were made in public, all
owners of wheels having a right to compete. Prony's Friction
Dynamometer was used, the brake acting on wheels 6 feet in diameter.
The point of contact with the scale beam (57.3 inches) described a
circumference of 30 feet. The supply main was 6,900 feet long, 22
inches in diameter, with a head of 386-1/2 feet at nozzle. A pressure
gauge placed a short distance back from the discharge nozzle (1.89
inches (?) in diameter) is said to have registered standing 165 pounds,
and running 162 pounds. The water from the wheel was discharged into a
flume 36 feet long, 36.5 inches wide, and 24 inches deep. There were
three check-boards placed in the flume below where the water entered.
The hook gauge, arranged on one side of the flume, was set 24 inches
back from the weir. The water passed freely around the hook and was
very quiet in the flume. A weir, 12 inches deep and 36-1/2 inches wide,
made of 1/8-inch iron, over which the water flowed without
contractions, was placed at the end of the flume. Francis' formula
for the discharge of water over weirs was adopted as the basis of the
calculations.
The following are the official returns :
