Valentine Democrat. (Valentine, Neb.) 1900-1930, 1909-12-09
NATIONS CLOCK
Careful Methods at Washington
Naval Observatory to In
sure Accuracy.
DELICATE MECHANISM IS USED
How Mean Time Is Obtained and the
Part Performed by Refers
Sidereal Timepiece.

A few moments before IL O'Clock
noon every day in the year a young
man walks into a certain room Of the
main building at the naval observa
tory, which is set UP on a hill in the
northwestern part Of the District OF
Columbia, the Boston Herald says. He
gIances at the various clocks in the
room and then goes over to a table
covered with electric apparatus.
He watches the clocks to his left
closely and waits for the hands tc
reach 1855. AS the second hand ap-
proaches the 60 on the dial he pre-
pares to shift a switch. The clock is
SO finely adjusted that when the sec
ond hand points to 60 it exactly marks
the beginning of a new minute and the
end of the Did.
AS it touches the 60 the switches
are thrown on. That starts a signal
that goes out instantaneously over
100000 miles Of telegraph lines. In
Washington, New York, Buffalo,
Cleveland, Newport, Baltimore, New
port News, Norfolk, Savannah, New
Orleans, Key West, Galveston, Chica-
go and elsewhere the time balls go up
on their poles. PEOPLE know that it
is five minutes before noon, Wash
ington time.
The clock which keeps the time in
the observatory ticks on. With each
tick there is a contact of electric
points. A circuit is closed and an
instrument on the table similar to a
telegraph sounder ticks away loudly.
1t goes on to the twenty-ninth sec
ond, then skips one tick, then resume
its steady %soundings until the last
five seconds, then there is another
gap. These gaps are for the purpose
Of giving listeners at other ends of
the great system Of wires a chance
to know what part of the minute the
clock is on. And so it goes up to the
last minute.
At the thirty-ninth second there is
again the skipping of one second. FL
nally the clock gets around to the fif-
tieth second. Then the circuit re-
mains open for ten seconds. There is
silence all along the telegraph wires.
The mean time is determined by as
Economical observations. When GER
tain stars pass the seventy-fifth meri-
dian, called the meridian of Washing
ton, it is a certain time. The oDer-
ator watches for the stars through a
telescope, the field of which is covered
with fine wires.
AS the stars reach a certain point
in transit the operator presses a key
recorded on a chronograph. The
chronograph consists of a cylinder
covered with a paper. A fountain pen
rests on the paper. 1t is held by an
arm attached to the mechanism. The
cylinder revolves once a minute and
the pen moves along the surface of
the paper, making a spiral line.
A sidereal clock of the finest make
is running in q vault underneath the
observatory. With each tick of the
there is a contact of two points.
These two points are attached to
that lead to an electrogramnet
attached to the arm that holds the pen
Of the c~hronograph. The clock is so
that each minute the pen is
to jump to one side. Conse-
there is no break in the line.
There are other breaks, too, when
he observer watches the stars cross
he lines in the field of the telescope.
The mean times thus recorded for |
each star after being corrected for er-
'ors is the clock time of the stars
ransit. Whatever difference there is
between the clock time and the side
cal time marked by the transit of the
stars is the error Of the clock. From
hese astronomical observations the
iidereal time is obtained. The error
mounts to but little, rarely being
more than from five one-hundredths
o ten one-hundredths of a second.