HYDROSTATICS. 



127 



liquids transmit pressure equally in all directions, may be 

 practically applied. 



The principle of the construction and action of the hydraulic press Is ex- 

 plained in the preceding paragraph (§ 291), and Fig. 105, represents a section 

 of its several parts. pj^ ^qq 



Fig. 106 represents the hydraulic press as constructed for practical purposes. 

 In a small cylinder, A, the piston of a forcing-pump, P, works by means of 

 the handle M. The cylinder of the forcing-pump, A, connects, by means of a 

 tube, K, leadinpr from its base, with a large cylinder, B. In this moves also 

 a piston, P, having its upper extremity attached to a movable iron plate, 

 which works freely up and down in a strong upright frame-work, Q. Be- 

 tween this plate and the top of the frame-work the substance to be pressed is 

 placed. To operate the press, water is raised in the forcing-pump. A, by 

 raising the handle M, from a small reservoir beneath it, a; by depressing the 

 handle, the water fiUing the small cylinder A is forced through a valve. H, 

 and the pipe K, into the larger cyhndcr B, where it acts to raise the larger 

 piston, and causes it to exert its whole force upon the object confined be- 

 tween the iron plate and the top of the frame- work. If the area of the base 

 of the piston p is a square inch in diameter, and the area of the base of the 

 piston P 1,000 square inches, then a downward pressure of one pound on p 

 will exert an upward pressure of 1,000 pounds on P. 



