s with use. The normal rule for the charge is 10 amperes
per square meter, and for the discharge double this quantity. This
apparatus has always given me on discharging 40 amperes at the E.M.F. of
1.85 volts during 60 or 65 minutes. The charge is effected in two hours up
to 20 amperes, without any appreciable loss of electricity.

"The points to be aimed at in an accumulator are longevity and energy, or,
rather, rapid yield per kilo. From both points of view accumulators of the
Plante type (and consequently those of Montaud) are far superior to those
of the Faure type. My opinion, therefore, is that the Montaud accumulator
is very practical, that it is a great improvement on the Plante type, and
that it can compete successfully with the other systems in use."--_Revue
Internationale de l'Electricite._

* * * * *

ELECTRIC REGISTERING APPARATUS FOR METEOROLOGICAL INSTRUMENTS.

Mr. E. Gime, whose name is not unknown to our readers, sends us a
description of a certain number of meteorological apparatus to which he has
applied a peculiar method of registering that it is of interest to make
known.

[Illustration: FIG. 1.--DIAGRAM OF GIME'S TELEMAREOGRAPH.]

Mr. Gime in the first place has devised a "telemareograph," that is to say,
an apparatus designed to register at a distance the curve of the motions of
the tide in a given place. The structure of this device, shown
diagramatically in Fig. 1, is very simple. It is divided into two distinct
parts--a transmitter and a registering apparatus. The transmitter consists
of a long glass tube, A, closed at one end and communicating through the
other with a receptacle filled with mercury. A barometric vacuum is formed
in this tube. The level of the open receptacle corresponds exactly to the
level of the lowest tide.

[Illustration: FIG. 2.--THE APPARATUS WITH THREE REGISTERING STATIONS.]

Pieces of iron wire projecting sufficiently in the interior to establish
good contacts with the column of mercury are fastened one millimeter apart
to the inner surface of the tube. These iron contacts are connected with
the divisions of a rheostat, R, arranged in a tight compartment surrounded
with paraffine, near the tube.

This rheostat is interposed in the general circuit. It is connected through
one extremity with the line, and through the other with a disk of copper,
which has a surface of one square meter, and is immersed in the sea.

The line,