Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1898-06-05
WIRELESS TELEGRAPHY.
Recent Results OF Practical Expert
ments I'm England.

N~SA4NSAA AAAA1SsJ
During the last few months the Solent
has been the scene of some interesting ex-
poriments in wireless telegraphy. Under
the direction Of Sgnor Blarconi two sta
tions have been fitted up-one In Bourne
mouth. just opposite the end Of the pier,
and the other at Alum Bay. in the Isle OF
Wight--and between these places, which
are about fourteen and a half miles apart,
regular communication has been main
tanned without the use OF any intervening
connecting wires. On occasion, an even
greater distance has been traversed, for
with portable instruments temporarily set
up on the cliffs at Swanage, ii has been
found possible TO speak with the station
a. Alum Bay-nearly eighteen miles
away But Signor Marconi does not be-
L0ye that tins represents anything like
the limits Up TO which his apparatus can
be worked, and he is now making the
necessary arrangements for exchanging
signals with Cherbourg, a distance OF
some sixty miles.
The instruments employed at Bourne
mouth and at Alum Bay are alike in all
essential respects. The only outward sign
al either place is a tall mast, some ~
feet high, from which depends a metal
lie CONDUCTOR. Sometimes this is a simple
wire; at others a narrow strip Of ordinary
wire netting has been tried as aitording
more electrical capacity, but there does
not appear 10 be any great difference In
the results. Inside the stations the first
piece OF apparatus that catches the eyel
IS an induction coil capable Of giving q
spark eight or ten inches long. This, |
with an appropriate battery and key 10
control the current. constitutes the send |
ing instrument. The discharge from the |
coil passes between two brass balls about
l-2 inches apart, thus giving rise 20 cleo
trO-nagn6tic waves, which are radiated In
oil directions. one Of the balls is con-
nected with the external conductor al
ready mentioned; the other Is put TO
earth. Some experimenters have en-
plOyed a series OF balls immersed
In oil to generate the waves but
Aarconrs experience is that the
Simpler arrangement he now en-
ploys is Just as efficient. The receiving
consist OF a coherer. relay,
and 4 Morse printer. The cOherer, the
function Of which Is 10 detect the pres
ence OF the electric waves that travel
through space from the sending station,
S. short piece OF glass tubing, into
which are sealed two silver pole-pieces.
Between these there is narrow space
Containing silver and nickel filings, and
The whole is exhausted Of air, not because
a vacuum directly fayOrs the sensitive
ness OF the instrument but TO prevent
OF the filings, which. Of course,
impairs their conductiuty. These pole
pieces are included In an electrical cir
cult with the relay and a single cell, and
IN aodluon, one OF them Is connected
with the external conductor and the
other with the earth. Normally, the CO.
hgrer does NOT copducf a cnrrant Ruf / ,
by virtue OF some action which Is not
yet fully understood, under the influence !
oi an electric wave. this condition is al
tered and current enabled TO pass [
through tho filings between the pole !
pieces. The ermature OF the relay Is them !
attracted, and the Morse printer or other [
Unable receiving instrument brought
INTO action /,
thus the signal is begun, but II has