138 



THEORY OF CONSTRUCTION AND SCIENTIFIC DESCRIPTION 



Fig. 3 represents the plan of the base or bottom of the frame ; it is 

 generally made of uniform thickness, Fig. 3. 



and of sufficient strength to withstand 

 the pressure, for be it understood, that 

 all the parts of the machine are sub- 

 jected to the same quantity of strain, 

 although it is exerted in different ways.* 



The circular perforations cc correspond to a a in the top of the 

 frame, and receive the upright bars in the same manner ; the perfora- 

 tions dddd, receive the screw bolts which fix the frame to the beams 

 of timber represented at GG, fig. \ ; the large perforation r receives 

 the cylinder, the upper extremity of which is furnished with a flanch, 

 for the purpose of fitting the circular swell around the perforation, 

 and preventing it from moving backwards during the operation of 

 the instrument. 



When the several parts which we have now described are fitted 

 together, they will present us with that portion of the drawing in 

 fig. 1 denominated " Elevation of the Press." 



A side view of the engine as thus com- 

 pleted, is represented in fig. 4, where, as is 

 usual in all such descriptions, the same letters 

 of the alphabet refer to the same parts of the 

 structure. 



F is the cylinder into which the fluid is 

 injected ; D the piston, on whose summit is 

 the pressing table E ; A one of the upright 

 rods or bars of malleable iron ; B the head of 

 the press, fixed to the upright bar A by means 

 of the cup-nut a; c the bottom, in which the 

 upright bar is similarly fixed ; and G a beam 

 of timber supporting the frame with all its 

 appendages. 



147. But the Hydrostatic Press as here 

 .described and constructed, must not be con- 

 sidered as fit for immediate action ; for it is 

 manifestly impossible to bore the interior of 

 the cylinder so truly, and to turn the piston 



Fig. 4. 



* The upright bars, cylinders, and connecting tubes, resist by tension, the pistons 

 by compression, and the pressing table, together with the top and bottom of the 

 frame, resist transversely. 



