PDF BOOK California gold mill practices

PDF BOOK California gold mill practices

By ED. B. PRESTON, M.E,,

MILL CONSTRUCTION.

After deciding on a suitable site, the surface should be removed down
to the bedrock and levelled off for the different floors. Solidity and
accessibility are the chief points to be observed in placing the different
parts of the mill. Where required, heavy stone walls should be erected
as buttresses. The foundation for the mortars and the proper erection
of the battery frames are points requiring particular attention. For
the mortar-block, a trench is prepared of suitable depth, preferably in
solid bedrock, proportioned to the height of the block, and wide enough
to leave about 2' of free space around it, which is later filled in with
concrete or tailings from the battery. These mortar-blocks vary from
8' to 15' in length and are dressed at the upper end to the size of the
bed-plate of the mortar. In California they can be obtained frequently
from a solid cut of a pine tree, or else consist of two or three sawed
blocks fitted and bolted together ; but where clear timber of the requisite
size is difficult to obtain, the block can be constructed of 2" plank,
as is done in the Black Hills in Dakota.

Link

http://www.archive.org/details/californiagoldmi00presrich