ion under consideration.
The lighter consists of a small, round, wooden box containing the
pile, and surmounted by a spirit lamp. A platinum spiral opposite the
wick serves for producing the light. The pile is a bichromate of
potash element, in which there is substituted for the liquid a
solution of bichromate identical with that used in bottle piles. The
zinc is suspended from a small lever, in which it is only necessary to
press slightly to bring the former in contact with the asbestos paste,
when, the zinc being attached, a current is set up which traverses the
spiral, heats it to redness, and lights the spirit. The pile, when
once charged, may be used for several hundred lightings. When the
spiral no longer becomes red hot, it is only necessary to replace the
paste--an operation of extreme simplicity. When the pressure is
removed from the little lever, the zinc, being raised, is no longer
acted upon by the liquid with which the asbestos is saturated. Mr
Desruelles is constructing upon the same principle a gas lighter, the
pile of which is fixed at the extremity of a handle whose length
varies with the height of the gas burners to be reached. These little
domestic apparatus are being exhibited at the Paris Electrical
Exhibition.

* * * * *

SOLENOID UNDERGROUND WIRES IN PHILADELPHIA.

The _Evening Bulletin_ of the 29th October has the following:

This afternoon a series of experiments were conducted at the Public
Buildings which will be of great interest to electricians all over the
country, and upon which the success of a number of underground
telegraph projects in different parts of the United States depends. In
all projects of this kind the problem which has given most trouble to
inventors has been to overcome the induction. In other words, electric
currents will leave their original conductors and pass to other
conductors which may be near at hand. This interchange of currents may
take place without seriously hindering ordinary telegraphy, as the
indicators are not delicate enough to detect the induction. When
telephones came into use, however, the induction became a great source
of trouble to electricians, it often being the case that the sounds
and influences from without were sufficient to drown out sounds in a
telephone. To-day's experiment was conducted by Mr. J.F. Shorey, a
well-known electrician, who exhibited Dr. Orazio Lugo's cables for
electric light, telephon