The Washington herald., 1914-06-21

NARNING against new wireless
w peril is made by a French writer.
He shows that vessels which car
ry explosives are in danger from their
own wireless plants. Whether this ap-
plies to warships, the writer is not pre-
pared to say. although he is inclined to
believe that the metal walls Of ammuni-
tion compartments serve as an effective
screen against electric waves. The
theory that a vessel or warship may be
blown up by wireless electricity gener-
ated at plant at distance is held to
be untenable
He SAYS:
Many vessels in peril have sum-
moned aid by means Of radio-telegraphic
signals. But care should be taken lest
the transmission plants installed on
board create a new source of danger, in
certain conditions and for certain ships.
On oil ships and others that carry in
hammable cargoes, especially when these
are volatile, such substances may take
fire from sparks that pass, by induction,
in various parts of the vessel, when the
operator is sending messages. The
Bureau of Navigation OF the Department
of Commerce of the United States has
foreseen this danger and has issued the
following instructions to radio-inspec-
tors:
when inspecting radio-telegraphic
plants on board tank steamships, oil
boats. and all other vessels carrying
substances that may give rise to mix
lures which can be exploded or ignited
by electric sparks, you will pay special
attention to the insulation of the an
tenna, you will examine metallic con-
facts. cables, electric material, and all
pieces in which the high-frequency cur
rents Of the radio-telegraphic plant are
likely to engender induced currents
If sparks pass, either between two
wires or across joints and air-intervals
in these pieces, the danger must be
pointed out to the commanding officer,
to the steamship company, and to the
wireless telegraph company
"'The production of sparks between
metallic objects in the neighborhood of
powerful wireless posts is a well-known
fact that is always taken into account
in the installation OF plants on land, On
vessels, when a post is working the
metal pieces near the antenna absorb by
induction a large part of the energy;
the metal guys, more or less parallel to
the antennae, are particularly the seat
of high-frequency currents that are very
Objectionable from the standpoint OF ef-
ficiency, since the current induced in
them is in the contrary direction to the
current that traverses the antenna at
the same moment, tending. to annul its
effect. To remedy this condition, the
stays are insulated from the ships hull
"Other pieces slightly insulated from
the hull by air spaces are also first put
into a state of electric tension and
finally discharge across the air space;
thus 1t is common to hear, in certain
parts of the boat, the cracking of sparks
At night, they may even be seen.
"In the French navy, also, 1t has been
asked whether the explosives in the
magazines may be considered as removed
from all danger of ignition by the cleo
trio waves engendered by the transmits
sion station on the ship. This question
is now being studied. 1t would appear
that when the explosives are shut up,
either In tight metal cases or simply In
metal ammunition boxes. there 10 moth