result, as
the electro-motor, like the centrifugal machine, is most efficient when
run at a high speed. The apparatus shown in the sketch consists
essentially of a perforated basket, A, which is slipped on to a cone
attached to the spindle, S, of an electro-motor, and held in position by
the nut, D. The casing, B, with its removable cover, C, serves to receive
the liquid driven out of the substance being dried. A flat form of the
ordinary Siemens H armature, E, revolves between the poles, P, of the
electro-magnets, M, which are connected by means of the base plate, I.
The brass cross-bar, G, carries the top bearing of the spindle, S, and
prevents the magnet poles from being drawn together.

[Illustration]

From four to six cells of a bichromate battery or Faure secondary battery
furnish sufficient power to run the machine at a high speed. An apparatus
with a copper basket four inches in diameter has been found extremely
useful in the laboratory for drying such substances as granulated
sulphate of copper and sulphate of iron and ammonia, but more especially
for drying sugar, which when crystallized in very small crystals cannot
be readily separated from the sirupy mother-liquor by any of the usual
laboratory appliances. For drying substances which act on copper the
basket may be made of platinum or ebonite; in the latter case, owing to
the increased size of the perforations, it may be necessary to line the
basket with platinum wire gauze or perforated parchment paper.

* * * * *

TRANSMISSION OF POWER BY ELECTRICITY.

The experiments of M. Marcel Deprez have entered on a decisive phase. The
dynamos are completed, and were put in place on the 20th October, when M.
Deprez carried out some preliminary tests in the presence of a commission
consisting of MM. Collignon, Inspector-General des Ponts et Chaussees;
Delebecque, Ingenieur en Chef du Materiel et de la Traction of the
Northern Railway of France; Contanini, engineer in the same company; and
Sartaux. The generating dynamos made by MM. Breguet, and the receiving
dynamos constructed by MM. Mignon and Rouart, were during a preliminary
trial placed side by side, one portion of the circuit being very short,
and the other twice the distance between La Chapelle and Creil, or
seventy miles. In future experiments the two dynamos will be placed in
their normal positions at each end of the line. The generating machine is
driven by a loc