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 Harz18 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 localities varying
according to the depth. At Schemnitz, in the Carpathian mountains, there
are three pumps, of which the lowest hfts 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 inclined
