It is
interposed between the pump and the lift. It consists of a vertical cylinder, in
which a piston travels, and which has to be loaded to a weight
equivalent to 450 lbs. per square inch. When the lift is not in operation,
the piston is raised to an extent proportionate to the quantity of water introduced,
which it returns to the lift when the ingress-cock of the latter is opened.
The diameter of the piston is 11.81 inches, and the stroke is 66.93 inches. The
volume of water contained is 26.2 gallons, and he pressure on the piston should
be 21.18 tons; the piston and cross-head weigh 1.18 ton. A load of 20 tons of
lead-ingots is suspended to the cross-head at the top of the piston. These can
be moved at will to facilitate the moving of the apparatus from place to place
on the works.
The accumulator illustrated in Fig. 3 admits of the use of a long cylinder of small
diameter. The weight of masonry M, rests
upon the cylinder C, and entirely surrounds the same.
No guide is therefore needed to control the vertical movement of the
weight, and the centre of gravity of the latter is situated low down. The
plate F is in two portions, consolidated by the screw-rods Z. The
upper joint has a stuffing-box, to which access may
be had through the cover K.