Charlevoix county herald., 1920-11-05
RADIO GUIDES
SHIPS IN FOG
Finders of Naval Stations On
Shore Give Angle, Mathe-
mates Does Rest.
WAR NECESSITY MOTHERED IT
Navigator Who Wishes to Know His
Latitude and Longitude Sends Out
WireIess Message and Listen
Ing Stations Give Bearings.


are losing their terrors for naval men.
In the not very distant past ship
that could navigate when the sun was
hidden became the subject Of wild sea-
farlng tales, but the radio direction
finder has eliminated many of the per-
lis due to the absence of the sun. To-
day q navigator who wishes to know
his latitude and longitude has only to
send the following wireless message:
"Thls is the (ship's name). Where am
II" And the data supplied by the
various listening stations Will give him
his bearings. The wireless direction
finder is not q new device-fnders
were patented as long ago as 1907
but war developments have empha-
sized the value of the instrument for
general navigation, says writer In
the New York Evening Post.
1t consists of loop Of wire at
tached to receiving machines. When
messages are being received the waves
set up current In the two sides of the
loop. If the waves strike both sides
of the coil equally there is no differ
ence in voltage. But when the waves
strike the coil in such manner that
there is a difference In voltage be-
tween the two sides Of the coil the re-
ceiving machines indicate the extent
of this difference. BY making pathe-
NAUTICAL calculations based on this diff
ference II is possible to determine the
direction of the ship which is sending
I'm relation to the port which Is re-
ceiving.
In order to locaue the ships posi-
ton exactly the data from at least
two receiving stations must be COM
pared and II is desirable that another
station send IT'S data to check the ac-
curacy of the finding
War Necessity Mothered II.
Especial attention was paid to the
development of the radio direction
finder during the war.when many fight
ing ships found that fog was almost
on q par with submarines as naval
menace. Experts thereupon expert
mented to discover a certain method
of giving a ship her reckoning" when
the sun was Obscured. The radio d.
rectiOn finder In Its most modern form
was the result. 1t is now proving its
great usefulness In time of peace.
Merchantmen are constantly using
our stations to find out where they
are" said naval officer. 81 should
say that for one warship that calls for
its bearings there are ten privately
owned vessels. Our radio direction
finding stations are really becoming
public service institutions"
The navy has erected and Is Operat-
ing stations at the entrance of almost
all Of the large commercial ports In
the country. There are several sta
tons near New York harbor, including
Montauk Point, Fire Island, Sandy
Hook and Far Rockaway. On clear
days the men on duty at these posts
have more or less of "sinecures," but
on a foggy day they are constantly at
work directing ships which have gone
astray. All the listening stations
transmit their information to head
quarters and headquarters tells the
skipper where he is.
Some elderly naval men were skep-
tical about the radio direction finder
when the navy department first intro
duced the device, but one experience
with the instrument usually suffices
to convince them of Its worth. Re-
Gently q new destroyer left Norfolk.
Va, bound for Newport, r. I.-ordi-
narily no great feat of navigation.
However, the compass was new and
untried, and the captain and the navi-
eating officer prayed for clear weather.
II Beats an Erratic Compass.
Despite their prayers they ran into
a heavy fog, and from the time they
left Cape Henry until they sighted
the reef lightship at the entrance to
Newport they could see nothing. New
ertheess, the run was made without
mshap, owing to the directions sent
out by the finding stations, and on
landing the officers, who had been
skeptical, were converts. 1t was dis
covered-later that the magnetic CON-
pass. by which they would have steered
under the old methods might have
brought them to grief, for II showed
an error of more than ten degrees.
1--WE are handicapped in extending
this work." remarked the naval officer,
'by lack of personnel. In fact, we've
been compelled to close up one or two
stations recently owing to shortage
of men. But eventually we hope to
have a station at practically every
moderately large portland that l
think, will cause making port In fogs
to be considered a very ordinary api
not at all dangerous achievement"