Cresco plain dealer. (Cresco, Howard County, Iowa) 1913-1945, 1918-03-01
SEA CLOCKS ARE
IN BIG DEMAND
War; Causes Shortage of Chro.
nometers Used in Ocean
Navigation.
NONE IN THE open MARKET
Price Jumps From $500 to $500 and
over-EnoIishman Who Perfected
instrument Won Prize Of $780,
600 and Thanks Of Mankind.

Washington.-Among the busiest
people supplying the United States
with war materials are the makers Of
chronometers. Great care and pre-
cision are necessary in turning out
these navigating instruments, which
are the most accurate portable time
keepers known to science.
Hundreds Of chronometers have gone
to the bottom of the ocean since
the war began. This alone would
cause shortage in the ordinary sup.
ply, while the equipping Of the new
American merchant marine is creating
an unprecedented demand for new in.
struments.
At present there are virtually no
chronometers to be had in the open
market. Before the war England sup
piled the world with most of its fine
chronometers.
In ordinary times a good chronome-
ter costs about $500. The present price
is $500 or better, according to the trade
made. The supply in this country
passes through the hands of a few ex.
perts, who are doing their utmost to
meet the demand.
From six months to year and a
half are necessary to make and adjust
a chronometer. The mechanism is of
the finest metals, and specially adapt.
ed to resistance to extremes Of tenn.
perature.
Errors Arc Noted.
No clock or watch has ever yet kept
perfect time, so there Is always q
slight gain or loss to q chrOnometer.
For this reason the thermometers rate
of daily gain or loss is determined by
observation ashore. and a card show.
ing the rate is made out, and deliv.
cred with the instrument. This rate
of error Is allowed in all notations Of
time made from the instrument for
working up observations made at sea.
The chronometer completes, with
the compass and sextant, the trio Of
indispensable instruments required in
modern navigation. BY its aid, longi.
tude, or the east or west position Of q
ship, is determined.
Longitude bafled all navigators I'm.
til the chronometer came into use in
1875. The ancients and later naviga.
tors, including all the great discover
ers, could find their latitude by oh.
servations Of the suns height, but they
could determine their longitude only
by "dead reckoning" or estimating
their ships progress from day to day
This system was uncertain, and
caused a great many shipwrecks.
Longitude is merely the difference
Of time between two points on the
earth's surface, and it became appar.
ent to students of the problem it pre-
sented that If an instrument could be
devised that would keep accurate time
at sea, it would be possible to find the
longitude Of a ships position whenever
weather conditions were favorable,
Time at the ship could be determined
by an east or west observation of the
sun, morning or afternoon, worked out
by accepted tables. If the time Of
given point on shore was known
aboard the ship, the difference in time
would give the longitude Of the ship.
England was the first nation to cope
with this great problem. In TIA it ap.
pointed commissioners for the Dis.
covery Of Longitude at Sea-" and au.
thorized the payment of large prizes
to stimulate research to the desired
end. This commission existed until
1923, and distributed more than $780,.
600 in prizes.
Wins $4,000 Prize.
The chief prize offered by the com
mission. 100000, was won by John
Harrison, Yorkshire matchmaker,
who spent his life in perfecting the
chronOmeter.
Harrison made the best watches in
England. Although of limited educa.
ton, he conducted many original re-
searches in the expansion Of metals,
in search of materials for an improved
watch or clock. that would prove i'm
pervious to changes Of temperature.
His first great feat was the production
Of "gridiron pendulum clock" the
first chronometer, which in 1875 he
took to the royal commission. It was
tested by the commission by being
sent on voyage to Lisbon.
The test was not decisive, and Har-
rison continued to work on his chro-
nometer, seeking the great prize for a
period of &c years. In 1861, when six
ty-eight years old, Harrison announced
that he had solved all problems in
volved in his work. He produced a
which the commission
sent on voyage to Jamaica, to test
for heat. 1t varied but two minutes
on the entire voyage of several months.
The commission demanded another
test, and the chronometer was sent to
varying but two-thirds of
a second a week in a voyage of five
Harrison had now fairly won the
prize, but he was paid only half of it,
the chronometer being given further
tests before when eighty