BREAKWATER DESIGN.
125
A dynamometer, lately devised by Major Gaillard of the Corps of
Engineers of the U.S. Army, possesses a cylinder fitted with an elastic
diaphragm and filled with liquid, which is in communication with a gauge.
The mobility of the fluid particles enables the wave-stroke to be administered
with less loss of energy than in the case of the solid plate, where the inertia
of the moving parts has to be overcome. But the appliance is characterised
by the same absence of conformity with actual conditions, to which attention
has already been drawn.
The maximum pressure actually recorded by the marine dynamometer
does not appear to have exceeded 3| tons per square foot. At Skerryvore
(in the Atlantic) a pressure of from 2^ to 2| tons per square foot has been
observed; at Bell Rock (German Ocean) 1| tons; at Dunbar (East Lothian)