maneuvers and withstands all sorts of moving about.

The small volume of which we have spoken is devoted more particularly to
electric navigation, for which M. Trouve specially designed the motor of
his invention, and by the aid of which he performed numerous experiments
on the ocean, on the Seine at Paris, and before Rouen and at Troyes. In
this latter case M. Trouve gained a medal of honor on the occasion of a
regatta. Our engraving represents him competing with the rowers of whom
he kept ahead with so distinguished success. We could not undertake to
enumerate all the inventions which we owe to M. Trouve; but we cannot,
however, omit mention of the pendulum escapement that beats the second
or half second without any variation in the length of the balance; of
the electric gyroscope constructed at the request of M. Louis Foucault;
of the electro-medical pocket-case; of the apparatus for determining the
most advantageous inclination to give a helix; of the electric bit for
stopping unruly horses; and of the universal caustic-holder. He has
given the electric polyscope features such that every cavity in the
human body may be explored by its aid. As for his electric motor, he
has given that a form that makes the rotation regular and suppresses
dead-centers--a result that he has obtained by utilizing the
eccentrization of the Siemens bobbin.

Although devoting himself mainly to improving his motor (which, by
the way, he has applied to the tricycle), M. Trouve does not disdain
telephony, but has introduced into the manufacture of magnets for the
purpose many valuable improvements.--_Electricite_.

[Illustration: TROUVE'S ELECTRIC BOAT COMPETING IN THE REGATTA AT
TROYES, AUG. 6, 1882.]