Evening public ledger. [volume] (Philadelphia [Pa.]) 1914-1942, 1919-06-28
new RADIO COMPASS
GUIDES SHIPS At SEA
Invention Enables Vessels to De-
termine Their Position by
Means Of Wireless
DEVISED BY NAVY MEN HERE

A new job for wireless-guidanre OF
ships at sea
BY the aid of that mysterious force
which spans oceans and girdles cont
nents. ship captains are coming safe
to port through storm and fog
The day is in sight when. through
this same medium of wireless, ship
NAV be brought clear across the At
lantic without sight of sun or stars.
on as straight course aN any Iald
with compass and sextant.
Wireless has been made to take the
place of compass. The magnetic com q
pass was the first great Invention III
the realm of physics which gave ald 1"
the navigator. Now comes the radio
commas" in many ways moro wonder
ful than its more familiar nam'sak".
This is .'Navy Day" For the first
time since the United states 'nt"reu
the war the Philadelphia Navy Var"
was thrown open to visitors ON n5m'n'
of n small admission fec, which Is to
be used for naval relief,
1t is especially fitting that the story
Of the radio compass should he tod
nublicly today for the first time, because
II was at the Philadelphia Navy lard
that the experiments were made WhI'h
psve the radio compass 10 the word.
This new instrument Of navigation
% one Of the few gifts made by the war
70 the human race. Experiments ''H'',
tuo veors ago, They had pr"gT'HHeH
sufficiently far during the lliH' "I!N
country was in the war tor th' r"u''
COMPASS to he of material uN' |" 'h'
United States Navy.
By the time the armiStic" was N'Gn'"
the compass had been brought I" "'E"
state of efficiency.
when our troops Of til" Twenty
.,rhtb Division began to com" home the
radio compass. installed i'll station,
along the coast near th" mouth ~
Delaware Bay. helped bring tnem III
safe through all kinds OF weather.
The radio compass Is no" an assure"
success. an acknowledged contribution
TO navigation and science. 1t r'nr'-
sents one of the big scientlh' Strid'N
taken through the war. For all time
II will he a factor in the safety ot NhipS
. at sea.
And II was worked out right here IN
philadelnbia. The wireless room at
League Island. one of the most interest
ing of the hundreds of interesting NIghtS
shown to navy yard visitors today saw
tho eerIv attempts to establish the
nrinciple on which the compass Is BASED.
Behind locked doors. in the drafting
room at League Island, the plans ana
snecifications for the first completed
comnoss we're drawn by a few technical
experts sworn to secrecy.
Details Yelled in Mystery
The radio compass has been one oI
be most carefully guarded naval Sc
crets of the war To this day it IS re-
parded as "highly confidential. an'
details of the compass itself. at least ~
tbey regard its mechanical principles
NAV not be revealed at this time.
II is a little difficult to make cieal
+ba workings Of the compass without
,,;oIatinC this confidence. Another name
Cor tbe device is CORRECTION finder.
This term may help make clear the man
nor in which the compass works.
In a word. the compass is an lnstru
ment which, in the hands of an expert
determines exactly the direction whenc
a radio impulse comes. The operate
hears a wireless call. With the "dircc
ton finder" he can tell whether tn
radio impulse came from right or LEI
or straight ahead. He can tell NOR
than this. The direction finder show
him the precise angle of incidence {
the call, measured mathematically
degrees.
But how does this information he
navigator establish his exact positio
in storm or fog when guiding stars a
hidden when drift and cross -curren,
have thrown hm out on his dead reel
oning,' when he cannot see the guiC
ing beam of light ship or hear the mu
fed bell of channel buoy?
1t is all perfectly simple. If the nav
gator knows the direction of his sh
from several points on shore. he easi
ran find himself on his navigate
charts.
Stations Constructed
Therefore the Navy Department h
built stations at various points alo
the coast and equipped them with rad
direction finders. For instance in t
Fourth Naval District. that in whi
Philadelphia is included, there are thu
stations guarding the entrance to Del
ware bay.
One is at Cape May, the main static
The others are across the bay at Ca
Henlopen, and at Bethany Beach, bC
in Delaware.
Imagine the captain Of a troopsl
making in for the Delaware Breakwat
He has gone through n succession
storms, and with big ship and seve
thousand soldiers entrusted to his ca
he is not quite as certain as he wo
like concerning his exact position.
He thinks he is somewhere of
Delaware Capes, but does not knC
Fog. a driving rain, and a following
add to his danger and perplexity.
He turns TO his wireless. call
Cape May sputters from his wirel
mast. 1t is answered. He asks for
bearings. He is ordered TO repeat
code letter and his request. Th
ont of the ether, in but a short tir
comes the information that he Is, say,
an angle of 05 degrees from Cape NJ
of So degrees from Cape Henlopen, {
of 63 degrees from Bethany Beach.
The rest is easy. His chart !
.nread before him in the chartroo
with a square and dividers he dra
Hines at the indicated degrees from