ch a bronze pinion is fixed, gearing
with the worm shown. The latter derives motion from a pair of bevel
wheels, which are in turn actuated from the pulley shown in the
engraving. The lever and the saw connected with it can be raised and
held up by a pawl while the work is being fixed. In small work the
weight of the lever itself is found sufficient to feed the saw, but in
heavier work it is found necessary to attach a weight on the end of
the lever. The machine is fitted with fast and loose pulleys, strap
fork and bar. We are informed that one of these machines is capable of
making 400 cuts through bars of Bessemer steel 4 in. diameter, each
cutting occupying six minutes on an average, without changing the
saw.--_Industries_.

* * * * *

A RAILWAY THROUGH THE ANDES.

The railway system of the Argentine Republic is separated from the
Chilian system by the chain of the Andes. The English contractors,
Messrs. Clark & Co., have undertaken to connect them by a line which
starts from Mendoza, the terminus of the Argentine system, and ends at
Santa Rosa in Chili, with a total length of 144 miles. The distance
from Buenos Ayres to Valparaiso will thus be reduced to 816 miles. The
Argentine lines are of 5.4 foot gauge, and those of Chili of 4.6 foot.

The line in course of construction traverses an extremely hilly
region. The starting and terminal points are at the levels of 2,338
feet (Mendoza) and 2,706 feet (Santa Rosa) above the sea; the lowest
neck of the chain is at the level of 11,287 feet.

Study having shown that a direction line without tunnels, and even
with the steepest gradients for traction by adhesion, would lead to a
considerable lengthening of the line, and would expose it to
avalanches and to obstructions by snow, there was adopted upon a
certain length a rack track of the Abt system, with gradients of 8 per
cent., and the neck is traversed by a tunnel 3 miles in length and
1,968 feet beneath the surface. The number and length of the tunnels
upon the two declivities, moreover, are considerable. They are all
provided with rack tracks. The first 80 miles, starting from Mendoza,
are exploited by adhesion, with maximum gradients of 21/2 per cent. Upon
the remaining 64 miles, traction can be effected either by adhesion or
racks.

[Illustration: FIG. 1.--REGION TRAVERSED BY THE RAILWAY THROUGH THE
ANDES.]

The track is of 3.28 foot gauge, and this will necessitate
tra