The Republican journal. [volume] (Belfast, Me.) 1829-current, 1885-07-23
Chronometers.
AN OLD SALT WATER SAILOR CHATS ABOl
THEM

AN OLD SALT WATER SAILOR CHATS ABOUT
THEM.
81 noticed the other day." remarked
an old salt water sailor, who now lives on
kossuth street, "that you had something
in the paper about chronometers. Now,
| happen to have had some experience in
the use of chronometers. People see
them in the jewelers. window, compare
their watches and pass. Few stop to
think of the relations they hold to Jife
and property on the ocean. Time was
when ships were guided to different parts
of the world without them, but at a
frightful sacrifice of time, and often of
ship, cargo and crew. Then the only
means they had of determining their Ion
gitude was by dead reckoning, and that
was very poor thing to depend on. The
old way was to get into the latitude of
the port sailed for and then steer east or
west as the case demanded. But the
chronometer has done away with all that.
Now captain can leave port and shade
his course to any part of the globe, and
know his true position, in clear weather,
every day. There are two gentleman, in
this city, whose fathers sailed from the
shores of Massachusetts bay, around
Cape Horn and Cape of Good Hope with
out chronometers, but there are very few
that would undertake it now. Some cap
tains own their chronometers, some hire
them, others belong to the ship. Some
carry two, and if the captain carries his
wife with him she has good cause to be
jealous Of the care and attention that her
husband gives to the chronometer. She
is only second in his thought on ship
board. | have known ii captain to take
the pillow from under his wite'S head to
set the chronometer on during a heavy
sea. | have often taken the chronometer
out OF its outer box and set it on pillows,
when we were handling heavy cargo, to
have a certain time to wind their chro-
nometers, generally at eight bells in the
morning. The captains wife, as a gen
eral thing, dare not look at it, and she
feels toward it accordingly. But there
are exceptions to this rule. There are
some captains wives that are first class
navigators. For instance, some years
ago the American ship Ne Plus Ultra left
Liverpool for Bombay Capt. Plummer
He had his wife and family with him.
After a few days he was taken with
paralytic shock. His wife nayigated the
ship successfully to her destination, bur
led two children on the passage, and lost
her husband three days after reaching
port. She and her only boy came home
in the ship that | was in. She looked
fn1ly ,,nh1a No hal
to be.
"Sailors have to be very careful with
their chronometers. A brass plate fits
over the keyhole, and works with
string, SO that as soon as the key is re-
moved it covers the hole on the instru-
ment so that no dust can possibly get
into the works Every chronometer
carries her record with her. The cover
forms almost half of the box in which
she sets. In that cover is where the
rates are kept from the time that she
LETT the makers hands. If she is good
chronometer you will find all her rates
there. After each voyage she is taken
to chronometer- maker and rerated, and
they often run for years on the same rate.
Now, if a chronometer gains one tenth
of a second to-day and loses one-tenth
tomorrow, which is a very small item,
she is no use for the purpose for which
she was intended, but she would be Just
the thing for a jewelers. window. But if,
on the other hand, she gained two hours
every twenty four hours, or lost the same,
and kept doing SO then you have first
class chronometer. This seems strange,
but in the first case you could not keep
track of her, and in the second case You
could. No matter what she gains or
loses as long as she keeps on doing the
same thing she is all that you want.
Some will say, Why are they 50 particu-
lar about time at sea ? But when it is
taken into consideration what proportion
a second is to a mile it will be plainly
seen why we have to be so particular.
There are fifteen degrees to the hour,
four minutes to the degree, fifteen miles
to the minute. and four seconds to the
mile, SO that an error of one second is
fourth OF mile.
"The trouble with chronometers is that
they are so affected by the temperature.
The slower the movement. and the colder
it is the faster she runs. We tell the
longitude by the chronometer. This is
set to Greenwich time, and the calcula-
tions are based on the principle that for
every degree of longitude east of Green
wich local time will be four minutes
faster, and for every degree west, four
minutes slower. The best chronometers
will run with surprising accuracy in all
temperatures, but they are not perfect
and as the slightest variation means much
to the navigator, he has his instrument
tested frequently, and the rate ascertain
ed. The rate is the variation of the
instrument with temperature, and by
observing temperature the captain keeps
a record Of the variations of his chro-
nometer, and thus correct the time as i'll
dicated by the instrument.
In testing chronometers they are sub
jected in turn to different degrees Of
temperature and their variation, scient-
iically observed, is registered inside the
cover there. Every good chronometer
will go accurately at two temperatures,
and can be adjusted to any given tenn
perature. For instance, one instrument
may be made to go accurately in tenn
perature of 40, and also in temperature
OF 50, at other temperatures being not so
accurate. BY constantly endeavoring to
keep his chronometer in its best temper
ature the captain is usually able to rely
confidently upon its accuracy, though
many wrecks have been caused by over
confidence in chronometers. Chicago
Herald Interview.