Variable Expanion (Scale 0.10 to 1).]

As shown in Fig. 5, there may be applied to this engine a variable
expansion of the Farcot type. The motor being a single acting one, a
single valve-plate suffices. This latter is, during its travel,
arrested at one end by a stop and at the other by a cam actuated by
the governor. Upon the axis of this cam there is keyed a gear wheel,
with an endless screw, which permits of regulating it by hand.

This engine, which runs at a pressure of from 5 to 6 kilogrammes,
makes 150 revolutions per minute and weighs 2,000 kilogrammes.
--_Annales Industrielles_.

* * * * *

FOOT LATHES.

We illustrate a foot lathe constructed by the Britannia Manufacturing
Company, of Colchester, and specially designed for use on board ships.
These lathes, says _Engineering_, are treble geared, in order that
work which cannot usually be done without steam power may be
accomplished by foot. For instance, they will turn a 24 inch wheel or
plate, or take a half-inch cut off a 3 inch shaft, much heavier work
than can ordinarily be done by such tools. They have 6 inch centers,
gaps 71/2 inches wide and 61/2 inches deep, beds 4 feet 6 inches long by
83/4 inches on the face and 6 inches in depth, and weigh 14 cwt. There
are three speeds on the cone pulley, 9 inches, 6 inches, and 4 inches
in diameter and 11/2 inches wide. The gear wheels are 9/16 inch pitch
and 11/2 inches wide on face. The steel leading screw is 11/2 inches in
diameter by 1/4 inch pitch. Smaller sizes are made for torpedo boats and
for places where space is limited.

[Illustration: LATHE FOR USE ON SHIPBOARD.]

* * * * *

ENDLESS TROUGH CONVEYER.

[Illustration]

The endless trough conveyer is one of the latest applications of
link-belting, consisting primarily of a heavy chain belt carried over
a pair of wheels, and in the intermediate space a truck on which the
train runs. This chain or belt is provided with pans which, as they
overlap, form an endless trough. Power being applied to revolve one of
the wheels, the whole belt is thereby set in motion and at once
becomes an endless trough conveyer. The accompanying engraving
illustrates a section of this conveyer. A few of the pans are removed,
to show the construction of the links; and above this a link and
coupler are shown on a larger scale. As will be seen, the link is
provided with wings, to form a rigid s