l82 



BOOK VI. 



A— Tappets of piston-rods. B— Cams of the barrel. C— Square upper parts 

 OF piston-rods. D— Lower rounded parts of piston-rods. E — Cross-beams. 

 F— Pipes, G— Apertures of pipes. H— Trough. (Fifth kind of pump— see p. i8i). 



