Evening star. [volume] (Washington, D.C.) 1854-1972, 1885-03-21
THE TIME NOT CHANGED.
why the Proposed Reform OF the Astro-
nomieal Day Has Not Been Effected
The Different Kinds OF Time of Which
Astronomers Have 20 Keep Track.

Why the Proposed Reform OF the Astro-
nomieal Day Has Not Been Effected
The Different Kinds OF Time of Which
Astronomers Have 70 Keep Track.
Whether the day should be considered as be-
ginning at noon or midnight is question which
Will probably never disturb the ordinary mortal
greatly, unless he has a note in bank, but 1t has
ior some time been matter Of grave discussion
among astronomers. The civil reckoning, which
Is the only reckoning known In the daily bust
ness of mankind on land, fixes the beginning of
each new day at midnight. This division of
Time has been found to accord well with the
practices of men. To begin the date at noon
would require change In all dated records at
most inconvenient hour
There are, however, other modes Of reckoning
besides that which prevails in the general az
begin at twelve o'clock, and is very elastic, one
Gay stretching sometimes over several calendar
oates. The astronomical day begins at noon.
reckonlng, differing from both the civil and the
astronomical reckoning. In this sea time the
new date began at noon, preceding the civil day
Dy WE'VE and the astronomical day by twenty
four hours.
The practical astronomer has a rather hard
tl1ile OF IT, between the different modes of reck-
on1ng OF which he has to keep track. He has
70 eat his dinner, go to bank or to church by
o one time, calculate his right ascensions by
coverles by still another IF his mind ever gave
way to the distractions incident to so many
modes MODES OF reckoning, all his right ascensions
would be. wrong ascensions; he would go to
bank at midnight, and get himself into contro-
Fersles by dating his discoveries day ahead.
sIDEREAL AND MEAN TIME
Sfdereal time is the time measured by the
regular march of the stars through the heavens
III has no reference to the sun or to solar time.
The sidereal day begins at any given place
when the vernal equinox passes the meridian
OF that place. Sidereal time is counted from
TO "a hours, the clocks which keep the time
having their dials divided into "a hour spaces.
once year, on March god, when the sun
crosses the equinox, sidereal time agrees with
solar time. The reader of astronomical works,
confusion in the terms apparent time" and
"mean time" Men who boast of the correct
ness of their watches generally speak of them
as oelng as true as the sun. AS a matter Of fact,
a watch that did not keep any better time than
the sun would be considered nowadays a very
be ahead of time during a portion o
the year and behind time at other sea-
sons, has led astronomers to ignore 1t alto
sun, which is always just on time. The time
gwen gwen by this imaginary, but prompt sun, is
Is called apparent time. Four times in a year
the real sun crosses the meridian just on time,
but during the intermediate seasons is fast or
slow, ranging from fifteen minutes on one side
oI the reckoning TO fifteen minutes on the other.
THE PROPOSED CHANGE OF TIME.
The international meridian conference, held
in this city last fall, besides establishing
prime meridian, sought to ameliorate the con-
dition of the astronomer somewhat and to Sc
cure harmony among astronomers of different
nations, by recommending that the astronomi-
cal day shall be considered as beginning at
midnight, the same the civil day Such
change, one accustomed only to the civil reck-
onin ng, might think could be effected without
much trouble, but the attempt to make the
change In this country has raised considerable
controversy. On the 4th Of last Dec. Rear Adm.
observatory, issued an order directing that ION
and after the LIST Of January, 1885 On accord
ance with the recommendation Of the inter-
cal day shall be considered as beginning at mid.
night, corresponding to the civil date.o' After
considerable correspondence on the subject,
however, Admiral Franklin, on the Goth Of De-
cember, suspended the execution Of the order
The correspondence in relation to the proposed
tary Chandler just before Congress adjourned.
and was referred to the committee on foreign
relations.
PROF. NEwCoMB's DIRECTIONS
Immediately after Admiral Franklin's order
changing the time for beginning the astronomi.
cal day was issued, Prof. Simon Newcomb,
superintendent of the Nautical Almanac, adj
dressed a letter to the Secretary of the Navy
arguing against the advisabilty of the change
at present. Referring to the recommends.
ton ton by the conference that the astronomical
proposes change in the method of count.
ing astronomical time which has come down to
US from antiquity, and which is now universal
noon as the moment from which the hours
were to be counted originated with Ptolerliy,
members of the conference seem to have sup
posed based solely upon the Inconvenience to the
a asst, ono OF changing his day at midnight,
raj method of measuring solar time"
The existing system he says permeates all the
volumes Of ephemerides and observations
which fill the library Of the astronomer He
points out that great confusion will result
In the future, and shows that if the change is
now made there will be for several wears a
lack of correspondence between the new system
and that ofthe American ephemeris which is
no change be made in the method of reckoning
time until by some International arrangement
a common date shall be fixed by ali nations for
the change.
HIPPARCHUS VERSUS PToLEMY.
Admiral Franklin, in letter replying to the
statements made by Prof. Newcomb, refers to
the fact that the Astronomer Royal Of England
proposed to make the change on the same date
as that directed by himself, $50 far as the count
ing of astronomical time from antiquity Is con.
cerned;' he said sit is the argument of eonserva.
tism which desires no change in an existing
order of affairs; yet, asserting to this argument.
we might refer to q still remOter antiouity-tO
the the time not Of Ptolemy but of Hpparshns,
twenty-four hours from midnight to midnight,
just as the conference has proposed" He ex.
pointed out by Prof. Newcomo could be obvi-
ated by care, and that 1t was eminently proper
that the nation which called the conferences
should be among the first to adopt its recon.
mendations.
THE VIEWS OF ASTRONOMERS
Then followed, in the correspondence sent to
the Senate, number Of letters from leading "a.
tronomers Of this country, evoked by a circular
sent out by Admiral Franklin, requesting an
expression Of views concerning the proposed
change Of the mode ofreckoning, and especially
as regards the date on which It would
ke best to introduce the new system.
Prot. Ormond Stone, Of the University of Vir.
ginia; Prof. III. A. Newton, of Yale College: Prof
u. w. Harrington, Of Ann Harbor: Prof G. A.
Young, OF Princeton; Prof. Louis Swift, of the
Warner Observatory; Prof. 8. r. Langley, of the
Allegheny Observatory, and Prof ]. q.
Porter. of the Cincinnati Observatory
wrote in favor of making the change I'M,
mediately. Prof E. C. Pickering, of Harvard
expressed the view that q general agreement
upon the subject was Of greater Importance
than the mode OF reckoning ITSELF Prof Ed
ward y Holden director Of the Washburn Or
seryatory, wrote recommending that the change
be delayed till other nations had legalized fbe
new day, and that in this country the change
was not advisable until 1890, or such time In
the future as will permit the American Enhe-
meris to be printed in accordance with the pro
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