216 MULE-HUNTING EXPEDITION. 
are for condensing the metal, communicating by 
square holes at the opposite corners; for instance, 
the right upper corner and lower left, and vice 
versd, so that the vapour has to perform a spiral 
course in its transit through the condensers. 
Leaving the chambers, the vapour is conducted 
through a large wooden cistern, into which a 
shower of water continually falls, and thence 
through a long flue and tall chimney carried far 
away up the hillside. 
The mercury is collected, as condensed, in 
gutters running into a long conduit outside the 
building, from which it drops into an iron pot 
sunk in the earth. As the pot fills, the mercury 
is conveyed to a store-tank that holds twenty 
tons. So great is its density, that a man sitting 
on a flat board floats about in the tank on a lake 
of mercury without its flowing over the edges 
of his raft. From this tank the metal is ladled 
out, and poured into iron flasks containing each 
seventy pounds (these flasks are made in Eng- 
land, and sent to New Almaden): in this state 
it is shipped for the various markets. 
Although every possible care has been taken 
to prevent the mercurial fumes from injuring the 
smelters, still a great deal of it is necessarily 
inhaled, most injurious to health. Clearing out 
