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BOOK VI. 



mortised at the lower end a short board ; this has an iron key which engages 

 a chain, and this chain again a pole-bar. This machine, which draws water 

 from a shaft two hundred and forty feet deep, is worked by thirty-two horses ; 

 eight of them work for four hours, and then these rest for twelve hours, and 

 the same number take their place. This kind of machine is employed at the 

 foot of the Harz^^ mountains and in the neighbourhood. Further, if 

 necessity arises, several pumps of this kind are often built for the purpose of 

 mining one vein, but arranged differently in different locahties varying 

 according to the depth. At Schemnitz, in the Carpathian mountains, there 

 are three pumps, of which the lowest lifts water from the lowest sump to 

 the first drains, through which it flows into the second sump ; the intermediate 

 one hfts from the second sump to the second drain, from which it flows into 

 the third sump ; and the upper one lifts it to the drains of the tunnel, through 

 which it flows away. This system of three machines of this kind is turned 

 by ninety-six horses ; these horses go down to the machines by an inchned 



A — Axle. B — Drum. C — Drawing-chain. D— Balls. E— Clamps. 

 ^^Melibocian, — the Harz. 



