Spirit of Jefferson. [volume] (Charles Town, Va. [W. Va.]) 1844-1948, 1912-02-13
Crude Devices Mariners Used In
Reckoning Time.
SANDGLASS MOST POPULAR.

If II Were Carefully Attended to the
Skipper Could Tell the DAYS Fairly
Well, but 1t Was Often JusgIed-The
First Chronometers.
To ascertain the time when at sea is
now matter of the utmost simplicity.
sailing days. and in order to acquire
even the vaguest idea of longitude and
time the seaman had recourse to curl
GUS devices.
Crude as these devices appear COM
pared with present day instruments,
they save the mariner from chaos and
destruction. and even If he could not
name the hour with any degree of GER
tainty he at least knew the day of the
week
Eciipses of the moon and the posi-
lions of the stars afforded little guide
to the skipper. who was, nevertheless,
greatly handicapped by his lack of as
Economical knowledge and the inferior
quality of his spyglass. Moreover.
eclipses could not be arranged for ev-
cry night in the week. and there were
dark nights when the stars could not
be seen. so various devices had to be
pressed into service.
The most popular form of old sea
clock was the sandglass. Many Of
these glasses were timed to run twen-
tyfour hours. and prior to the ship
leaving land the glass was set exactly
at noon. If 1t were carefully watched
and turned as soon as the sand ran
down the skipper could reckon the
days with fair accuracy.
Side by side with the large glass were
placed half hour and minute glasses.
The man at the helm carefully watch
ed this old sea clock and announced
the time at regular intervals by strik-
ing bell. 1t was customary to esti-
mate the duration of any incident by
so many glasses. ITO fog the glass"
was an operation very congenial to
lazy seamen. 1t consisted in turning
the glass before all the sand had run
down so that the watch was appre-
Gladly shortened
When the twenty-four hour glass
was employed a little juggling was in
dulged in for the purpose of finding
the longitude The difference between
the twentyfour hour glass and the
time by the sun was estimated and
this difference was held to represent
the longitude east or west, according
as the suns time might be before or
after the time returned by the glass.
Taking the sun" was a weird and
wonderful operation. Clumsy quad
rants were utilized. and toward mid
day the captain appeared on deck to
perform his solemn duty After much
screwing of eyes and waggling of the
quadrant the captain would bawl out
to the mate. Make it - bellsT the
number varying according to personal
idiosyncrasies
A demand for more satisfactory
device for estimating time at sea was
responsible for experiments being
made with pendulum clocks, though
with little success The interest of
inventors was aroused when the Eng
lish government in TIA offered f10,-
600 to any one inventing method of
reckoning longitude to within de-
gree. or sixty miles: f15,000 If within
forty miles and 100000 If within thirty
miles
John Harrison, an obscure Yorkshire
carpenter. who had achieved local
reputation by repairing and cleaning
clocks. came forward with chronom-
eter which at once attracted attention.
Through the influence of DR.. HALEY he
was enabled to make a voyage in a
government vessel to Lisbon. where be
succeeded in determining the longitude
to within degree 80 minutes.
For this achievement he was grant
ed $500 to enable him to proceed with
his invention After thirty years hard
toll he produced n chronometer on
which the present marine chronometer
is based His invention was shaped
like a large watch. and in 1861 Har-
rison's son embarked for Jamaica in
order to carry out tests On the voy-
seconds in error. and during the whole
trip from Portsmouth to jamaica and
back the variation was only minute
54.5 seconds
The accuracy Of the chronometer
thus enabled the longitude to be deter
mined within eighteen miles. result
which exceeded the admiralty's most
sanguine expectations After further
demonstrations an act Of parliament
was passed IN 1865 awarding Harrison
f20.0G0 half of the money to be paid
as soon as he explained how his time
keeper was constructed and the re-
mainder when the government was
convinced that these l!mekeepers could
be made by others Despite the full
fiIment Of these conditions. Harrison
had TO wait several years before the
money was paid over
Larcum Kendall. who had been Har-
risons apprentice and who was ulti-
mately his successor. followed on the
lines laid down by his master and pro
duced chronometer which was used
BY Captain Cook during his daring
voyage In the Resolution OF this
chronometer Cook wrote. Our longi-
tude can never be erroneous while we
have so good guide as Hr. Kendars
watch
Various horelogists have introduced
20 many improvements that little trace
Of Harrisons model Is 20 be discerned
in the modern thermometer. though TO