ully, and packed up in tough
rawhide bags, so as to make small compact parcels some 18 in. to 2 ft.
long, and 8 in. to 12 in. thick, each containing about 1 cwt. Two of such
bags form a mule load, slung across the animal's back.

The second and third qualities of ore are taken direct to the smelting
works; and where these are situated at some distance from the mines, as at
Huanchaca and Guadalupe, the transport is effected by means of strong but
lightly built iron carts, specially constructed to meet the heavy wear and
tear consequent upon the rough mountain roads. These two classes of ores
are either treated separately, or mixed together in such proportion as is
found by experience to be most suitable for the smelting process.

On its arrival at the reduction works the ore is taken direct to the stamp
mill. At the Huanchaca works there are sixty-five heads of stamps, each
head weighing about 500 lb., with five heads in each battery, and crushing
about 50 cwt. per head per twenty-four hours. The ore is stamped dry,
without water, requiring no coffers; this is a decided advantage as
regards first cost, owing to the great weight of the coffers, from 2 to 3
tons--a very heavy item when the cost of transport from Europe at about
50_l_. per ton is considered. As fast as the ore is stamped, it is
shoveled out by hand, and thrown upon inclined sieves of forty holes per
lineal inch; the stuff which will not pass through the mesh is returned to
the stamps.

Dry stamping may be said to be almost a necessity in dealing with these
rich silver ores, as with the employment of water there is a great loss of
silver, owing to the finer particles being carried away in suspension, and
thus getting mixed with the slimes, from which it is exceedingly difficult
to recover them, especially in those remote regions where the cost of
maintaining large ore-dressing establishments is very heavy. Dry stamping,
however, presents many serious drawbacks, some of which could probably be
eliminated if they received proper attention. For instance, the very fine
dust, which rises in a dense cloud during the operation of stamping, not
only settles down on all parts of the machinery, interfering with its
proper working, so that some part of the battery is nearly always stopped
for repairs, but is also the cause of serious inconvenience to the
workmen. At the Huanchaca mines, owing to the presence of galena or
sulphide of lead in the ores, this fine dust is