iberal lubricating arrangements are
fitted to provide for long runs, while uniformity of speed is provided
for by a Pickering governor. The high pressure cylinder is 4 in. in
diameter, and the low pressure cylinder is 7 in. in diameter. The
stroke in each case is 4 in.

[Illustration: Fig. 2.]

The dynamo is designed to feed sixty lamps of 16 candle power each,
the current being 60 amperes at 50 volts. The armature is of the drum
type. The peculiar feature of it is that grooves are planed in the
laminated core from end to end, and in these grooves the conductors,
which are of ribbon section, are laid. Slips of insulating material
are laid between the coils and the dovetailed mouths of the grooves
are closed with bone or vulcanized fiber, or other dielectric. At each
end of the core there are fitted non-magnetic covers. At the
commutator end the cover is like a truncated cone, and incloses the
connections completely. One end of the cone is supported on the end
plate of the armature and the other end on a ring on the commutator. A
bell-shaped cover incloses the conductors at the other end of the
armature. The result is that the conductors are completely incased,
protected from all mechanical injury, and positively driven. They can
neither be displaced nor abraded. The conductors on the magnet coils
are likewise carefully protected from harm by metal coverings. These
dynamos are made in sixteen sizes, of which seven sizes are designed
to feed more than 100 lamps, the largest serving for 600 lamps.

[Illustration: Fig. 3.]

Messrs. Easton & Anderson are showing machinery of this type at the
Crystal Palace Electrical Exhibition now open in
London.--_Engineering_.

* * * * *

CHLORINE GAS AND SODA BY THE ELECTROLYTIC PROCESS.

The decomposition of a solution of common salt, and its conversion
into chlorine gas and caustic soda solution by means of an electric
current, has long been a study with electro-chemists. Experimentally
it has often been effected, but so far as we are aware, the success of
this method of production has never until now been demonstrated on a
sound commercial basis. The solution of this important industrial
problem is due to Mr. James Greenwood, who has been engaged in the
development of electro-chemical processes for many years. The outcome
of this is that Mr. Greenwood has now perfected an electrolytic
process for the direct production of caustic soda and