88 The Drainage of Fens and Lozu Lands, 



CHAPTER VI. 



THE ARCHIMEDIAN SCREW PUMP. 



These pumps, although frequently used for lifting water from 

 drains for emptying and cleaning them out, and other similar 

 yurposes, have seldom been applied in this country for the 

 permanent drainage of land. They derive their name from 

 Archimedes, the Syracusan, who lived 287 B.C., and invented 

 this machine, during his stay in Egypt, for draining and 

 irrigating land. They were subsequently used by the Romans, 

 The Dutch have used them very extensively in Holland for 

 raising water for the drainage of the Polders. 



The screw pump consists of three parts. A solid cylinder 

 in the centre, called the core, to which is attached one or more 

 spiral screws, and sometimes an external case. The number 

 of screws running round the core varies from one in the 

 simplest machine, to three or four in those of larger character. 

 The ends of the core terminate in gudgeons which revolve in 

 bearings, the lower one fixed under the water, and the upper 

 on a beam spanning the delivery opening. As the efficiency 

 of this machine is not affected by the speed at which it runs 

 it is suitable for being driven by steam, wind, or hand power. 

 In small pumps a crank handle is attached to the upper part 

 of the core, and on this a pole with an eye through the centre, 

 bushed with metal, is attached, the pole having cross handles 

 at each end. One man works at the handle on the core, and 

 one or more at each of the handles on the pole. It is 

 reckoned that one man can raise in an hour at the rate of 

 1738 cubic feet of water i foot high, the pump making forty 

 revolutions a minute. If worked by machinery, the pump is 



