Every evening, Wilmington daily commercial., 1920-04-13
WIRELESS RINGS BELLS
EIGHTY MILES AWAY
Marconi Expert Devises Radio
Aid for Ships in Distress
at Sea.

London. April 12-1he Marconi Go.
mas devised for use on ships "callingup
system which is mainly intended still
further 10 advance the object for which
wireless is required To be installed IN
shins-thc saving of life at sea. A ship n
distress will in future he enabled auto
maticaIly % ring alarm bells on board any
vossels within range to come speedily
To her assistance.
I'm the past, in order to insure that
signals should be heard. IL WAS neces-
sary for an operator always to he on duty
wearing the usual telephone headpece.
Ii he left his post for few minutes only,
an important call might be lost, because
the sound produced in the telephone by
wireless signals. received under normal
conditions. was inaudible at a very short
distance away from the apparatus. That
being 81. u was essential To have on board
ships equipped with wireless installations
AZ least three operators who divided the
dav and night into shifts of DUTY The
present Marconi calling system enables
a ship 10 call up all ships within range,
even II no operator or watcher Is on duty
IN those other ships IN the same way rs
the ringing Of the bell of the ordinary
telephone indicates that message awaits
delivery
An exhibition Of this emergency call
lng dcvidc was gwen recently at the
Marconi Works, Chelmsford. Major Me
Cnllum. of the Mardoni Co. explained
that the problem which had 10 he solved
was the production Of AN automatic trans
mittcr which would send out n special
signal with mathematical accuracy, and
an equally reliable receiver which would
respond ia this signal aud this signal only
II was the loss of the Titanic that impressed
N, company hc said, with the necessity
for such a device. During the war all the
energies oi the company were conccn-
tratcd on war work. and after the signing
nf the armlstlcc the problem was agoin
taken IN hand. with satisfactory results.
For the purpose OF the experiment an
out station. fitted wih both the new
wireless calling device and wireless telc-
phuny was put up THIRTY miles from helm
fond at Shaliord close 10 Cambridge
Communications were FIRST exchanged
between Chclm-ford and Shalford by the
company, wireless telephony with a.
much speed and accuracy a> with an Or
,linary telephone Then the special mes
sage were sent frem Shatord. which not
only set bells - Chelmsford gong but
also explode charge Of gunpowder and
flashlights
Probably the use Of the calling appa-
ratus Will ~ confined - ships in difficult
Ihl- will insure general and immediate
attention hcmg gwen to emergency calls |
such a. = q : and "T 4 II the ice
warning Without entering INTO tech !
meal description at the system, II i Suff- |
cient 10 say that when the emergency |
arises the automatic key viii he pressed and |
n q fraction Of a mnu'c all tho alarm bells /
on ships fitted with tho receiver and within /
range any distance up 10 eighty miles Will /
he set ringing, after which the transmitting |
operator can send particulars as TO the |
ship and it, position lvCn It hv some /
mIschance these particulars cannot be !
supplied. the warning message itself will /
indicate the location Of the vessel in dis /
'rcss Another result which the system (
makes possible y reduction Of tho wire /
less staff on board ships which apart from
the receiving of distress signals do MOI
require 10 maintain a continuous wireless
watch