The daily union. [volume] (Washington [D.C.]) 1845-1857, 1849-01-07
OFFICIAL.
NATIONAL OBSERVATORY,

Washington, Jan. S, ls49.
SIR: have the honor of making known to you a
most important discovery for astronomy which has been
made by DR. Locke of Ohio, and of asking authority from
Observatory
The discovery consists in the invention of smagnetic
clock, by means of which, seconds of time may be d.
vided into hundredlhs with much accuracy and pre-
clson as the machlnst, with rule and compass, sub
divide an inch of space.
Nor do its powers end here They are such that the
astronomer in New Orleans, ST. Louis, Boston, and Of
every other place which the magnetic telegraph reaches,
may make his observation, and at the same moment
this clock, here in Washington, to record the in
slant with wonderful precision
Thus, the astronomer Boston observes the transit of
star il fits through the field of his instrument and
crosses the meridian of that place Instead of looking
clock before him, and noting time in the usual way he
touches key and the clock here subdvdes his seconds
to the mlnuest fraction and records the time with
ring accuracy.
The astronomer in Washington waits for the same star
10 his meridian; and as it does, DR. Lockes mag
netic clock is again touched it divides the seconds and
| records the time for him with equal precision.
The difference between these Two times is the longitude
of Boston from the meridian of Washington.
The astronomers in New Orleans and st Louis, and
every other place within the reach Of the magnetic wires,
may wait for the same star; and it to their
ridan, they have but to touch key, and straghtway
| this central magnetic clock tells their longitude
And thus this problem, which has vexed astronomers
and navgators and perpexed the world for ages. is re-
duced at once, by American ingenuity, to form and
method the most simple and accurate.
While the process is much simp6ed the results
greatly refined In one night the longitude may be
determined with far accuracy by means Of the mag
netc telegraph and clock, than by years of obser
walton according to any other method that has been
| tried.
poran discovery and It belongs that class Of achieve
| mens by which the most beautiful and enduring monu-
ments are erected TO national honor and greatness 1t is
national trumph and my feelings OF professional pride
will not allow me to pass by without calling your at
tenton to the garland that has been hung about II by the
navy.
TO the navy belongs the honor of having first applied
the magnetic telegraph to the determination of longitude
Five six years ago Captain Wilkes of the navy, used
II tor determining the difference of longitude between this
city and Baltimore. This was the first time had been
| applied TO such purposes and It was a great improve
ment upon the methods which, up TO that me had been
used for finding the longitude for it reduced the results
down TO the accuracy with which the time between the
ticks OF the second hand could be measured the face Of
| the clock by the eye and the ear.
And thus the honor of being the first to convert the
magnetic telegraph into an astronomical instrument and
that too into one OF great practical value and Importance
was secured by one of its officers to the American navy
Though the errors of the problem greatly reduced
by this discovery there were however, small sources Of
error still remaining, and il was left for Dr. Locke, for
mery an officer OF the navy also, to devise Of
eliminating them so completely that there is
trace left IN the resutsso free they from doubt
and uncertainty The probable of longitude deter
mined with Dir. Lockes clock, is brought within such
narrow limits, that if, while the astronomer in St Louis
or elsewhere were operating with the magnetic clock
here for his Longitude the observer in Washington
10 move IRON one instrument to another in this building
\
once and whether he had moved to the east or the
would be told by the clock and appear in the resulting
| longitude.
Dr. Locke was formerly member of the medical corps
OIL he navy, and as such spent portion of his early
manhood and prime years of his life at sea- is there
ore not surprising that sailors should be quick lay hold
OF the problem of longitude through any improved means
that may be offered for its solution. Every see
The Importance OF accurate determinations of longitude
but sailors both see and feel It,
In his letter to me describing his clock, and giving
account OF ITS performances Dr. Locke kindly offers put
up one at this Observatory
II would be OF ncalcuiable service and advantage 1t
would increase the accuracy of results and greatly null
hpy them IN numbers. With this clock one observer
could do more and better work. than two can now An
illustration OF the value Of such clock just now occurs
am wiring at night; the sky is very clear, and it is
The nfs lar night for observations that have had this
year Ihe wind IS very high, and the observers have
Just come IN TO say they cannot hear the clock account
OF the wind, and therefore they cannot observe. Now
Is not necessary TO hear, to see the magnetic
clock; and had we one could work quite as well in
windy as in calm weather
While, therefore, of Dr. Locke's magnetic clocks
would be OF such value 10 the Observatory, il would
without at all nterfern. with that value, be of incacu
able advantage to the public generally for wherever
IN any part OF the country there transit instrument
and line OF wires. this clock may bs used BY the OBJ
server at that instrument, not only for recording his
observations, but alec for determining his longitude from
the ssFl'l n the country md thus Il would without