The Sunday telegram. [volume] (Clarksburg, W. Va.) 1914-1927, 1914-12-20

Tue WUuuL1u&s OF these lubtEuIneu(s
Twas taken. as they are expected to
aid the astronomer in detecting In
Inaccuracies OF hundredth part Of d
second OF time. The telescope Is pro
yided with reticle for observing star
transits. There is small metal rraIne
crossed by q number OF metal threads
lof spidery web consistency II the
lreticle has ten threads II gives ter
observations OF each star as It eros
lses the range of vision The average
time OF these ten observations is ac-
cepted as more reliable than the rec
ord Of u single one.
An instrument known as chron-
ograph is used in recording observa-
tions and comparing them with clock
lime The chfonograph IS e cylinder
caused to revolYe by driving clock.
1t is encased in a sheet OF paper. and
pen is caused to bear upon the pa
per as the cylinder ievolyes. The
pen has an advance motion, so II left
to itself would produce a spiral. The
arm of the electro magnet is attach
ed to the pen In such way that
whenever a circuit is broken the pen
produces a jog in the spiral. The
clock :; arranged to make Jog at
every double beat, so the pen records
la regular series Of joys representing
Intervals Of two seconds OF time.
The star observer is provided with
a key by which he can break the cir
cult when the star is upon successive
threads OF the reticle. By so doing
he will have record on the sheet
which will represent the time Of the
Istar transit. AS the right ascension
of the star is definitely known, any
difference between that and the clock
time is known to be an error in the
clock. A slight allowance has to be
made for the personality OF the OBJ
servers. One man may press the key
ia little sooner or later than another.
This fact was taken into consideration
In the series of simultaneous obser-
vations made in Paris and Washing
ton. which have just been computed.
The accuracy of the clocks is Sc
cured by continuous tests.
The naval observatory has four
clocks which are regarded as prac--.
|tically perfect. AS changes OF tenn
perature tend to produce slight inac-
vault in which the temperature is
maintained at 81 degrees Fahrenheit
throughout the year The variance
of the temperature of these clocks
during the last year amounted to only
four-tenths Of a degree, and the max
imum variation in the accuracy of
the clocks was only eighteen hunu-
redths of a second during that per
iod.
Sending out the time signals from
the observatory is an interesting
daily occurrence. These are sent by
the beats OF a transmitting clock not
far behind those in the vaults in ac-
curacy. The clock is provided with
la toothed wheel attached to the sec
onds pinion. The teeth on the wheel
represent seconds and none is pro-
vided for the 29th. 56th.. seth, 51tn,
IS and 50 seconds. When the teeth
revolve they push a spring opening
an electric circuit which sends a sig
nal along numerous circuits including
the Western Union and Postal Tele-
graph companies and the wireless
station at Arlington. BY means OF
these, each beat of the clock is re-
corded In many places, except the
beats for which the teeth of the
wheel are omitted. This omission is
to enable the one receiving the mes
sage to identify the minutes and half
minutes. II
The signals are sent out each day,
beginning five minutes before noon.
The telegraph companies have their
wires cleared for this purpose In adj
dition to the noon time service a
night signal service has been inau-
gurated from Arlington which is sent
out at 9:55 each night The carrying
power Of radio signals is much great
er at night than in the day: time and
these signals have been received thou
sands Of miles away The signals
can be received by anyone who is suf-
ficiently interested to erect a wireless
station to receive them, and thous-
ands OF private stations of this kind
have been established in this coun-
try within the last year. The obser-
vatory encourages such efforts ana
has recently issued circular giving
full directions for establishing such
stations with definite descriptions of
the apparatus required
1t is rather interesting to know that
the first recorded demand for correct
time in this country came not from
scientific men or railroad companies
who might be supposed to be direct
ly interested. 1t was made. by a jew
leIer, r. n Hershfield, of Fort Leay-
enworth. Kansas, who wrote to the
national observatory in 1876, asking
that acme means be devised by which
he could secure correct time by tel
egraph in order that he might be able
to give correct time to the people of
that city. The letter was referred to
the Western Union Telegraph Com
pany with the statement that the OBJ
servatory would always be glad to
render time service IL arrange
ments could be made for transmit
ting it throughout ahe country. The
present daily time service has grown
from this.