Evening star. [volume] (Washington, D.C.) 1854-1972, 1881-12-23
ADJUSTING SHIPS, COMpssSES.
Delicate work in Which Few Wen Are
Expert-StOlen American Ideas.


Delicate Work in Which Few Wen Are
Expert-StoIen American Ideas.
There are plenty Of British ships supplied
with American compasses. but never heard of
an American ship fitted with British compass"
said an ancient mariner to Sun reporter 1T
is a curious fact" he continued. that although
you can buy first-rate compass for S45 it
sometimes costs 500 to adjust it to a ship. This
has become very difficult operation since the
Introduction of iron ships which at first played
the deuce with all the cOmpasses The British
admiralty paid good deal Of attention to the
subject. and their manual is standard work
But the business of adjusting compasses is con-
fined to a very few experts. who get their own
prices. The late Capt. COmstock was famous
adJuster OF compasses. and Capt. Fry is now the
leading man employed i'm New York The pre-
else method of ad justment is a secret that has
been well kept. Generally it consists in placing
various MAGNETS near the compass, SO as to
cOunteract the influence of adjacent masses of
iron. To do this the ship must be taken to some
point where there are landmarks at known
points OF the compass. The vessel is swung to
each point and the deviations of the compass
are noted and corrected.
''There is difference between the variation
of a compass and the deviation The variation
is the result of natural causes-mainly variation
opposition OF the earth'S surface. The varia-
tons Oh the compass at different distances and
directions from the poles are carefully noted and
every capable navigator makes allowance for
them in laying his course The deviations are
caused by local Influences. If vessel is living
at the dock where there are large quantities of
iron, the compasses will deviate. But they will
come all right wilon the ship sails away from the
dock. Sometimes iron in the cargo will play
the deuce with compasses and risk the loss of a
ship. cargo of petroleum in tin cans has been
known to deviate the cOmpasses.
"While the mariners compass is of ancient
origin and the Chinese made cOmpasses long
before the time of Christ by floating a magne-
tiZed needle in a vessel of water there are
some modern Improvements of marked value of
American invention. One of these is a device
to counteract the deviation of compasses caused
by motion OF the ship. In rough weather this
motion is apt to set the needle wabbling. In
some cases the needle may stagger or fly six or
eight points. Then it is difficult to tell which
way ship is going. To Obviate this difficulty,
an American inventor, Mr.. E. S. Richie, of BOs-
ton. invented a liquid compass. The needle is
completely surrounded with alcohol. This does
not effect it's magnetic power but prevents I'M
steady motion. 1t is as impossible for the needle
card to wObble in the alcohol as it is for you to
run in the water. Sometimes the liquid COM
passes have been known to freeze in very cold
weather. To Obviate this, another American in
ventiOn. the Baker compass, mas been introduced.
This can not be frozen at any temperature. The
liquid used is transparent preparation of
petroleum.
"a very ingenious device is used in hqu i'd
cOmpasses to provide againt the danger of crack
ing tine glass by expansion of the liquid. There
is an elastic chamber which keeps the space sur
rounding the needle always filled with liquid,
but takes off the strain of expansion. The best
way to mount a needle in compasses has been
found to be to place jewel in the needle card
with little depression, which fits over brass
point on which the needle swings. Although
this is never oiled it has been found impossible
to detect the least friction. Occasionally
the brass point needs renewing. Sometimes
cOmpasses get lazy from loss OF magnetic power.
About once year the needle must be remagne-
tiZed.
"As the safety and quick passage of ship
depend in great measure on the correctness Of
the compass it is common thing for ship to
carry three or more eompasses One is q steer
ing compass, another is standard compass, and
In iron ships they have adopted the device of
putting the compass at the masthead, 80 as to
get it as far as possible away from the influence
OF the iron in the vessel. Big ships carry what
is called an .'azimuth" compass. This is rugged
with sight vanes, SO that by taking observations
~ the sun navigator may ascertain his bear
ings and correct his compass. Men who can ad-
Just compasses are exceedingly jealous Of their