Evening star. [volume] (Washington, D.C.) 1854-1972, 1923-04-08
ny JAMES A BUCHANAN.

| are about to hear the final
tick that means noon to all the coun-
y, try. You are In the time-transmit-
| ting room Of the National Observa-
| tory. out Massachusetts, avenue way.
You have been waiting for five
! minutes to hear the signal that sets
all the real good clocks IN the coun-
! try back on standard time-that Is,
! correct time.
You have watched the officers in
charge gaze at the little pen point
that marks on a paper scroll the
breaks in the ticks. for every 80
often there is a break that warns
| that the setting time is near. You
note the difference in the sound of
the ticks and tocks, or at least you
think you do. but really they are
just the same as they were when you
first heard them. The fact that you
are listening so intently causes them
TO have a different sound
Before attempting TO describe the
manner IN which the correct time is
secured and lest the reader may
think that this is to be a story con-
nected with astronomy only. IT is
only fnir to state that the naval OBJ
| servatory does many other valuable
things besides showing the stars to
! visitors on Thursday nights. II is
! one OF the most important institu-
tons in the country, and in develop
| ing the line of work that Is being
carried on there. the Navy has rem
! dered a signal service TO the coun-
| try. 1t has made possible many
hat hnl he ht,S In
of the nation. the men who sail the
seas, in fact all lines OF endeavor
have beneted
| The men in charge, from the first
| cay OF its activities to the present
| time. are men Of the Navy. men who
have been trained in this line of
| work. 1t is not an institution that
should be handled by any other
| branch of the government, for while
| the Navy is in charge, citizens know
! that accuracy will be the watchword.
| In addition to the peace-time pur-
/ suits OF these men. they are every
| day being trained to meet any emer-
/ gency that may arise. and the wis
| dom Of keeping the observatory un-
| der the jurisdiction of the Navy was
! made most apparent in the last war
! in which this country engaged.
! Attempts have been made. most Of
! them years ago, TO have this branch
| of the governments activities placed
| under a semi official direction, out
| congress has always frowned upon
I the suggestion. and the efficient
structure that the Navy has been
building for eighty-odd years stands
4 20 SL- do
! votion to duty of those who man our
Wsrships in time of strife.
! j
1NNE must not gather the impress
~ sion that the only thing they do
over at the Observatory is to check
! up on the moon. sun and stars for
they do many interesting things in
| the different buildings that are set
| in the circle of 1000 feet. a plot
that contains approximately seventy
| acres.
| The determination Of time is most
| interesting study. The observations
for time are made at the Observatory
] two or three times a week, and be-
fore attempting to describe the
, method. it may be well TO state that
! the layman does in seconds or half
| seconds. They divide into hundreds
of a second. There is no guess work.
They are not satisfied to have the
! time out a quarter Of second. They
| leave nothing to chance. With them
! time is an exact science
| The observations consist essentially
; OF determining the time Of transit
across the meridian OF certain Sc
] iected stars. according to a standard
clock. The American Ephemeris and
| Nautical Almanac, an annual volume
published by the Observatory, gives
! the correct times Of transits of
these stars and the error OF the
standard clock is found by compar-
ing the clock times and the almanac
| times.
! The observations are made with an
instrument provided with the most
refined mechanism for observing the
transits OF the stars. II you happen
| to be gazing through one Of these in
| struments and see what appears TO
be two rather thick lines across the
| field of vision you are gazing at two
thin cobwebs, lines that could not be
seen with the naked eye unless your
4 sense Of sight was most acute. Each
star yields a value of the error Of
| the standard clock, and so accurately
are the observations made that a
series of stars ordinarily gives re-
suits agreeing within a few hun
dredths Of a second.
| Let US now take a look at the
standard clock and vault, for this
master clock" and its companions
| are too delicate to be placed out in
the room whore we saw the time be-
ing flashed over river and hill.
/ through valleys and across oceans
| The standard clock is one OF the
three astronomical clocks running I'M
der constant temperature and air
pressure in small underground
vault. This vault is constructed in a
most ingenious manner. There Is the
outer wall of brick construction. You
| enter through an air-tight door and
are in a very small space. There is
another door Of like character ahead
OF you. You close that and face still
another. Because you closed the
doors. you have not changed the tenn
perature. You now face tho last door
and this you open, finding yourself
in a small room the temperature Of
which is eighty-five degrees. The
room Is kept at that point by Their
mostatic control.
You see three clocks, all OF them
mounted on solid pillars They SIT
on glass bottoms and run in partial
vacuum. They do not look like the
ordinary clock that you have in your