The annual meeting of the French Society of Physics, the success of
which is continually increasing, took place this year in the salons of
the Observatory, which were kindly placed at the Society's disposal by
Admiral Mouchez.

There were three consecutive sessions, the one of Tuesday, April 15,
being set apart for the members of the Association, the one of the
16th for the invited guests of Admiral Mouchez, and that of the 17th
for the invited guests of the Society. The salons were partially
lighted by the Siemens differential arc, continuous current lamps, and
partially by the Swan incandescent lamp supplied by a distributing
machine that permitted of the lamps being lighted and extinguished at
will without changing the normal operation of all the rest. Many
apparatus figured at this exhibition, but we shall on the present
occasion merely call attention to those that presented a certain
character of novelty or of originality.

Among the apparatus that we shall reserve a description of for the
present was Messrs. Richard Bros.' registering thermometer designed
for the Concarneau laboratory, an instrument which, when sunk at one
mile from the coast, and to a depth of 40 meters, will give a diagram
of the temperature of the ocean at that depth; and Mr. Hospitalier's
continuous electrical indicators, designed for making known from a
distance such mechanical or physical phenomena as velocities, levels,
temperatures, pressures, etc.

Among the most important of the apparatus exhibited we must reckon Mr.
Cailletet's devices for liquefying gases, and those of Mr. Mascart for