s deepest,
and which consequently the older miners must have had most trouble in
reaching. Here were set up two Letestu pumps that were actuated by a
four-horse wheel.

These pumps lifted 50 cubic meters per hour. All except the pump chambers
and pipes was made of wood on the spot. The water that was lifted was
carried away from the works in a flume 160 meters in length, which
likewise removed the water from the motive wheels.

For the service of the same excavation two simple acting inclined planes
were installed that were moved by a four-horse wheel. Fig. 2 gives a
general view of the arrangement.

The tracks of these planes were made of wood. Steel rails, however, had
been brought for the cars, along with the cables and the metallic parts of
the windlass; but all else was made upon the spot, including all the
wooden pulleys for transmitting motion from the wheel to the windlasses.

This excavation reached bottom at a depth of 16 meters. The second touched
bottom at about 10 meters, and gave access to a subterranean canal, which
was followed for about 20 meters. The extraction of sand was effected here
by an inclined plane moved by a Gramme machine. The generatrix had to make
1,500 revolutions, and be set in motion by an overshot wheel. As time was
wanting, it became necessary to diminish to as great a degree as possible
the number of parts to be employed in the transmission of motion, and
since there was an abundance of water, a velocity of 15 revolutions was
accepted for the wheel, which, with a total fall of 4.8 meters, had to
give a power of eight horses. A three meter pulley was placed upon the
shaft of the wheel. This was made of freshly cut wood that had been
exposed to the sun. In order to give it sufficient stability and prevent
its warping, it was placed against the wheel in such a way as to rest upon
the latter's spokes. This rendered it necessary to give up the idea of
using a belt, since it was not possible to prevent its getting wet. Cords
could not be found in the country, and so it was necessary to make use of
a too heavy chain, which was in no wise intended for such a purpose, and
which at a velocity of 15 revolutions began to swing and necessarily
absorbed much power. The large pulley drove one of 0.4 m. upon an
intermediate shaft. Upon this latter a 2.6 m. wooden pulley directly
drove, through a belt, the 0.2 m. pulley of the generatrix.

From this may be judged what the country's resources are.