Hydrostatics. 41 



be proved by experiment, having a false bottom 

 to each of the vessels supported by an iron rod 

 fixed to a balance, as in fig. 13 ; in which case it 

 will be found that the same weight, at the oppo- 

 site end of the balance, is necessary to support 

 the bottom in each. 



The hydrostatic bellows is a very pleasing 

 machine, constructed upon this principle. It 

 consists of two strong boards, united by leather, 

 almost in the manner of a common bellows, only 

 that for convenience its form is round (see 

 Plate IV. fig. 14.) In this figure a is a pipe, 

 which goes into the inside of the bellows, and 

 u is a weight laid upon the upper board. If 

 then water is poured into the pipe , the weight 

 will be lifted up ; and if the pipe was still taller, 

 a greater weight would be raised. By a very 

 small force exerted in this manner, that is, by 

 water conveyed through a very small perpendi- 

 cular tube, Dr. Goldsmith relates that he has 

 seen a very strong hogshead burst in pieces, and 

 the water scattered about with incredible force. 



To show that this principle in hydrostatics is 

 not without practical utility, it is only necessary 

 to mention, that upon the plan of the hydro- 

 static bellows a press has been constructed of 

 immense power, see fig. 15, in which a is a 

 strong cast iron cylinder, ground smooth on the 

 inner side, and e is a piston or moveable plug, 

 fitting very tight within it. c is a common forcing 

 pump, in which the water ascends through a 



