The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1903-04-17

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Morse for the transference Of the frs;
signals.
The difference in longitude of two
places being simply the difference of
true time at those points, it is only nee
essary to determine the time. and com
pare the figures by one of various meth
DDS in use by the United states Coast
and Geodetic Survey. The Pacif1c Com
mercia1 cable between Honolulu and
San Francisco was used for the first
time for this purpose last night.
Temporary astronomical observa-
tories have been established at Homo
lulu and San Francisco at which the
errors Of chronometers are determined
by the astronomical instrument. using
the chronographic method. The transit.
which is erected in the little observa-
tory on the Naval Station grounds,
rests upon a cement pier to lessen
vibrations. and consists of a telescope
which moves nearly in the true merid-
ian. II the instrument could be plac-
ed in perfect adjustment and moved in
the true meridian. then the observa-
ton of a single star over the merid-
ian. would at once determine the cor
rection OF the chronometer as the true
time OF the passage of the star Is
known It being impossible to have
this instrument in such perfect adjust
ment, 1t is necessary to observe both
north and south stars in order to de-
termine their deviation from the true
meridian. and also to observe stars. in
reversed positions on the axis to deter
mine the deviation OF the lines in the
telescope from the true central position.
The third correction is determined by
a very delicate level placed upon the
pivots of the instrument which deter
mines their deviation from a purely
horizontal plane. From these observa-
tons. corrections are applied to each
star, which win give its times of pas
sage over the true meridian. and the
difference Of these times and the true
time Of passage of the star. is a cor
rection TO the chronometer
These observations are all made by !
the observer holding in his hand |
small telegraph key which he taps as
the stars. pass the lines of the telescope. |
and the record is made upon sheet of
paper placed upon a drum revolving
once minute. and the face time of
the chronometer is made electrically |
and automatically.
In order to compare the times at |
the two stations a telegraphic connec-
ton is made between the stations and |
the cable offices at Honolulu and San |
Francisco. chronometers NaIso being
placed at the cable Offices. The ap- /
paratus is also provided to make an
electric record of the face time of the !
upon the fillet used in re- i
ceiving messages over the cable. The !
errors of the chronometers at the cable 1
Offices are determined by comparing
them over the short land lines with
the chronometers at the observatories.
and then these chrononeters at the
cable offices are compared by a system
0I StEli.S over lAAc IeADtNt Gil tAE ACNo%0
being automatically made upon the
1nets.
In clcer to eliminate the personal
equation OF an observer. it is necessary
hat the differences between the two
observers shall be determined and
therefore Mr.. Smith after having OBJ
tanned results on five nights here VIII
return to San Francisco and Mr.. Morse j
will come TO Honolulu and the work
viii continue on i've more nights. The I
transit, as it now rests. points directly
north and south.
The Pacific Commercial Gable Com !
pany has courteously extended the use
II It's cable to the United States gov
eminent to assist in this research. free
IF cost 1