456 *f he compound Pump. [Book Vlf, 



is a fucker S, defigned for the fame ufe as in the 

 fimple fucking pump. In the body of the pump is 

 a pifton M, not pierced as the preceding, but folid, 

 and put in action by the aid of the rod x X, and of 

 the lever Y X Z, which has its point of fupport, or 

 fiilcrum, at Z. At the fide of the pump, and towards 

 the bottom of its body, is adapted a raifing pipe H R, 

 furnifhed with a fucker s near its bafe, and with a 

 fpout R near its fuperior extremity. This pump 

 ought to be placed in fuch a manner that the lower 

 extremity. only of the afpiration pipe H V fhould be 

 immerfed under water. 



It is eafy to perceive that the firft action of this 

 pump will be the fame as that of the fucking pump, 

 \vhich has been defcribedj for if the pifton M is 

 raifed by putting the lever Y X Z in the fituation 

 y u Z, the column of air which refts above will be 

 elevated ; the air which is in the afpiration- pipe will 

 become, by that means, rarer than the exterior air. 

 The latter then prefies more forcibly upon the furface 

 of the water A A, and carries it, after fome ftrokes 

 of the pifton, into the body of the pump ; when it 

 is arrived there, if the pifton M is lowered, the fucker 

 S will clofe, and the water is forced along the raifing- 

 pipe H R, by the rifing of the fucker j, which, as foon 

 as the preflure ceafes, falls again from its own weight 

 and that of the water above it. 



This pump is very convenient, on account of its 

 body being placed out of water, which affords an op- 

 portunity of making the neceffary repairs with facility, 

 and alfo on account of its being capable of carrying, 

 water to any height which may be required : in order 

 to effect this, all that is necefiary is, to lengthen die 

 raifing-pipe, and to augment the power which puts 



the 



