Mr. Seidler has taken out a patent for an engine, which he calls a hydraulic engine, but which we think should rather be styled a pneumatic engine, as raising water is merely one of the objects to which he proposes to apply the principle, which is that of employing compressed air as a medium for transmitting the power of any prime mover to machinery at a distance, or in situations where the ordi nary modes of connexion would be inconvenient or impracticable. The principle itself is very old, having been employed by Pepin as noticed under the word Aia. The engraving on the next page represents the application of the prin ciple to the purpose of raising water from any depth, and through straight or circuitous passages. a a represents a cylinder, in which a piston, p, works by means of a steam engine or other power. h g are copper pipes, forming a communication between the cylin der as and the cast iron tank or vessel kl; oo is a large delivery pipe, of copper or other material, through which the water is conveyed from the tank, and discharged; at r is an air-tight partition, dividing the tank into two parts, k and 1; and a s are two air-tight partitions, proceeding from the top nearly to the bottom of the tank ; e is a two way cock, for effecting an alternate communication between a and k, and between a and L The other parts of the machine will be ex plained in the following description of its action. Suppose the piston p to be raised from its present posi tion in the cylinder, the air above it will be conveyed through the valve c, and the pipe h into the vessel k, and force the water con tained therein through the valve t, up the pipe o o, while air will be supplied to the cylinder below the piston through the valve b. When
the piston descends, the air will pass from the lower to the upper side of it by the valve d ; this operation is to be continued till all the water is forced out of k, when the two-way cock e must be turned to change the communication through the valve c to the pipes 9, and the part of the tank 1 at the same time; the air which was forced into k will be permitted to re-enter the cylinder through the pipe w, as shown by the dotted lines in the cock e, so that no air will be required to enter at the valve b except at the commencement of the operation, or when any of the air is discharged with the water, or otherwise dissipated. When the air is liberated from the receptacle k of the tank, it will be again filled with water through the valve m, the valve i being shut by the pressure of the water in the pipe o o. During this time, the water in 1 will be forced through the valve a; in the same manner from k, through the valve i. The cock e to be turned by the hand or by the machinery, after such a number of strokes of the piston in the cylinder as is sufficient to displace the water in one division of the tank. For machines for raising water, see PUMPS and WATER WORKS.