men
at a time, which is simply a very long truck, the four wheels of which
run on the tramway provided. Their trucks, or "cars," are much more
capacious than ours in Victoria generally, and they are made in the old
style, whereby the body of the truck is only lifted, whilst the wheels
remain on the rails. In connection with winding machinery I may add
that the Americans, as a rule, prefer steam to animal or manual power;
consequently whims, whips, and windlasses are not seen anywhere, but
compact coupled engines of various sizes and different power form the
first steps towards speedy mining. This is rather an important matter
for the engineering trade, and when it is considered how much time and
expense is lost with the whim or whips, there cannot be the least doubt
of the preference that should be given to suitable engines for
preliminary opening of mines and their future exploitation, either from
the surface or underground. The chief engineer of the Belcher Mining
Company reports : "That a shaft having two compartments of 6 feet by 6
feet each had been sunk 1,000 feet vertical and 400 feet on the incline
in seventeen months by means of a coupled 7-inch cylinder winding
engine with an expenditure of only one cord of firewood for each
twenty-four hours." To continue the subject of safety catches and
hooks, I may state that quite a variety of these appliances are in use,
inasmuch as mine superintendents are, in the absence of specific laws
relating to mining accidents, liable at common law for any want of
preventative for avoiding accidents. Some of these apparatus are geared
with two pairs of coupled concentric springs acting on levers, which
force grips or catches against the guides centrically or at their two
sides ; hand levers are also in use besides. The experience, however,
with steel springs has been to prove their losing the elasticity
needed, through the steel crystallizing and acquiring a subsequent
brittleness from the continuous vibrations they are subjected to.
Rubber bands, spiral springs, buffers of the same material, are
preferred in many cases where intense cold does not interfere with
their utility. In some very deep shafts, where the ordinary rigid wood
or iron guides or skids are dispensed with, four wire ropes are instead
stretched at the corners of the shaft or compartment, and, as the cages
have each eight loops fixed at the top and bottom corners, much room is
gained, and, instead of four grips, as in the old manner, eight grips
are provided by the use of rubber bands, springs, or buffers, acting on
levers, which force wedge-like grips outwards and underneath each loop,
thereby arresting the falling cage without that dangerous shock common
to most other catches.
The safety hooks were of the ordinary kind, and therefore call for no remark.
Section IV.
MINIKG AND CRUSHING OF AURIFEROUS ORES.
The
general use of modern rock-boring machines and nitro-glycerine
explosives necessitates, in California, the reduction of these so
produced massive blocks of stone by means of " stone-breakers " as in
use at Clunes and Bendigo. These supply the circular self-feeders with
small ore, and the latter is fed, as needs be, into the boxes, or "
mortars." The Califomian and Nevadian batteries are arranged in mortars
with five stampers in each ; their round stamp-heads and shoes are
fixed to the turned " stems," or shanks, in a similar manner as ours,
and the following parts form a stamper:—Plate II., the stem, the tappet
and gib, the stamp-head or socket, and the shoe;
