62 TECHNOLOGY. 
by means of which a reciprocating motion is given to the piston. This 
machine is generally employed for the purpose of raising water, the driving 
piston being connected with the plunger of a pump. The construction and 
play of it are best illustrated by reference to pl. 13, fig. 15, which represents 
a section of a machine of this kind constructed by Reichenbach in the 
salt-works at Ilfang in Bavaria, which forces the saline water to an elevation 
of 1,218 feet. igs. 16, 17, 18,19, 20, and 21, represent details of the same. 
The column of water which acts as the motive power enters by the main- 
pipe, A (jig. 15), the supply being regulated by the throttle-valve, a, and 
after having performed its work it is discharged by the pipe,w. The whole 
mechanism is in the four verticals, a’, o', ¥’, 0’; in a’ is the pipe B branching 
off from the main-pipe, and communicating with the horizontal pipe, B’, 
when the stop-cock, 6, is opened. In the vertical c’ is the pipe, c, which 
is seen on a larger scale in fig. 21; it communicates with the pipes, np’, and 
contains two small pistons, d and d@’, both on the same rod, p, and drawn 
in fig. 15 in their lowest position. In the vertical, Fr’, is the distributing box, 
consisting of two cylinders, r and « u, the lower one having a larger diameter ; 
in the former moves the piston x, in the latter the pistons, x and M, all fixed 
in the same vertical axis. In the vertical, 0’, are the three cylinders, P, aq, 
and Rr, the first of which contains the counter-piston, s, the second the main 
driving piston, Tr, and the third the plunger, v, which forces the saline water 
to the required elevation. The cylinders Pp and r have equal diameters, 
and are both open at top, while q is open at the bottom. The cylinder, r, 
of the forcing pump, the suction pipe, x, the chamber for the puppet valves, 
x and a’, and the pipe, y, are supported by a strong wall. 
We will now suppose all the parts of the mechanism to be in the positions 
represented in jig. 15; the stop-cock @’ is closed, 6 is open, and there is no 
air in any of the pipes. The water from the main-pipe fills the cylinders, 
@, F, Pp, and the pipes, B, B’, q@’, and vp’. The small pistons, d and d’, are at 
rest, having equal diameters and suffering equal upward and downward 
pressures. The pressure on the unequal pistons, x and L, is greatest in the 
downward direction, but their descent is prevented by the rod, m. The 
water therefore passes through Q’ to the main piston, 1, which is driven 
downwards by a pressure equal to the weight of a column of water having 
the diameter of the piston, T, and the height of the main pipe. In its descent, 
T carries with it the counter-piston, s, and the plunger, uv; the action of the 
latter is to force the saline water into the conduit pipe, y, while the former 
expels the water contained in p through the spout, 7. As the main piston 
arrives at its lowest point, a small pin, e’, on the rod ¢ (figs. 15 and 19), 
pushes down the end, ’, of the lever, »’n, and thereby raises the opposite 
end, ©, and the rod, p, with the piston,d and @'. The water will now enter 
below the piston, m, through c, and will neutralize the pressure from above 
upon L; the pressure upon x will therefore carry all three alternating pistons 
rapidly upwards, cutting off the communication of Q’ with a, and establish- 
ing that between a and P’, which will immediately produce an ascent of the 
counter-piston, s, and consequently of r and u, the water in q passing through 
q’ and 1 into the discharge pipe, x. When Tt reaches again its highest position 
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