II

, the working-beam or lever: it is made of two or more large logs of timber, bent together at each end, and kept at the distance of 8 or 9 inches from each other in the middle by the gudgeon, as represented in the Plate. The arch-heads, II, at the ends, are for giving a perpendicular direction to the chains of the piston and pump-rods.

K, the pump-rod which works in the sucking pump.

L, and draws the water from the bottom of the pit to the surface.

M, a cistern, into which the water drawn out of the pit is conducted by a trough, so as to keep it always full: and the superfluous water is carried off by another trough.

N, the jack-head pump, which is a sucking-pump wrought by a small lever or working-beam, by means of a chain connected to the great beam or lever near the arch g at the inner end, and the pump-rod at the outer end. This pump commonly stands near the corner of the front of the house, and raises the column of water up to the cistern O, into which it is conducted by a trough.

O, the jack-head cistern for supplying the injection, which is always kept full by the pump N: it is sixed so high as to give the jet a sufficient velocity into the cylinder when the cock is opened. This cistern has a pipe on the opposite side for conveying away the supersluous water.