Fairhaven herald. [volume] (Fairhaven, Wash.) 1890-????, 1892-02-19

gether with Its Journey Around the
Sun, Are the Disturbing FactOrs-No
Watch Is Perfectly Reliable.
If there is one single scientific problem
upon which more than another people
appear to get mixed that problem is
time Standard time, local time, sun
time are exceedingly difficult problems
for the public to puzzle over, and when
sidereal time enters the calculation the
case is hopeless indeed. ] have fire.
quently of late seen so many letters ad-
dressed this and other journals, all
touching upon one or the other of these
chronological questions, that have con-
cluded short note explaining the main
points of difference would be, at any
rate, timely. If it only suggests to the
young men in the business offices the
idea Of going to work at a. m, local
mean time, and leaving OFF promptly at
p. m, Pacific standard time, the ques
ton will have been shown TO possess
practical side. The application Of it
however, is purely matter Of taste.
Well, to come to time, the great chro-
] nOmeter and regulator in chief to the
/ business, social and scientific world is the
earth itself. Turning upon its axis in the
period which we divide into twenty-four
hours, the sun appears to cross the me-
ridian Of each place on the globe once in
that interval The moment at which it
crosses the meridian Of any place Green
wich), for example, is termed "local ap-
parent noon" at that place. This would
be all very well if the earth and sun re-
manned fixed in their relative positions;
or if the earth, completing, as it does, an
annual revolution about the sun, did so
uniformly in a perfect circle and that
circle were in the same plane with the
motion Of daily rotation. Then the sue
cessive intervals between the meridian
passages of the sun at Greenwich would
all be equal, and perfect chronometer
set at 10 hrs, 0 min, Sec, when the
sun transited today would indicate pre-
} cisely the same instant for apparent
noon" at every date.
: MOTIONS OF THE EARTH,
But the earths path around the sun is
not perfect circle; it Is an ellipse, and
the motion in one portion Of the ellipse is
: more rapid than in another, and this
causes a slight variation in the intervals
between the solar passages. Again, the
plane of the earth's path around the sun,
or the elliptic, is inclined 2315 dogs. to
} the plane of the equator in which the
, daily rotation takes place, and conse-
quently twice a year the intervals of
b apparent noon are each about twenty
seconds greater and twice a year about
! twenty seconds less than twenty-fOur
hours. To explain just why this results
, would require more of an investigation
! into astronomical principles than is here
contemplated; but it is so, nevertheless,
} and any text book will elucidate the rea-
e sons. A combination of the two effects
, causes the sun to be apparently slow
7 fourteen minutes in February and fast
sixteen minutes in November. But in
the course of a year the average comes
out all right, and therefore a 'mean
solar day" of exactly twenty-four hours
f is adopted in the almanacs and used for
0 all purposes. This accounts for the diff
l ference between mean time and sun time
A regulator keeps the former; sun dial
: indicates the latter.
A few years ago (or prior to 1884 every
large city in the United States had its
= own local time, and this was for each
place the true mean solar time, obtained
/ as above indicated
Q REGULATING TIME.
e Consequently, man travelling west
# ward from Washington would find hi;
y watch fast, as follows: At Chicago, A.
: minutes at Omaha, hour 10 minutes
at Denver, hour SO minutes; at Salt
{ Lake City, hours 20 minutes, and final
: ly, at San Francisco, 3 hours minutes
: 1t will readily be recalled how much
}. annoyance was occasioned by all thes,
various corrections, both to trainmeI
| and travellers. About the year men
toned great reform was inaugurated
Nowadays a traveller going westward
finds his watch fast from time to time
q but only the hour hand is i'll error. Al
/ the clocks in the country indicate th'
r: minute and second of Greenwich meal
d time, but the hour is changed for eacl
i Is dogs. Of longitude. Washington tim,
:. is hours slow Of Greenwich; Chicago
, hours; Denver, hours. In San Fran
y cisco we are hours slow Of the prim
meridian All the intermediate cite
q and towns are run ON one system or an
n other, according to their location Il
lie longitude, the standards being eastern
!. central, mountain anu Pacific time. Al
the time pieces on the coast are set b.
= Pacific standard time. which is 8 hour
slow of Greenwich mean time There
fore, watch which is set at San Fran
G -,
sun dial Is still minutes AZ second
slow of a Pacific standard time clock
al because we are that much IN longitud
or west of the l20th meridian, which form
a the eastern boundary of northern Cal
~ fornia and on which only is the "Paciti
o time" coincident with local mean time.
IN San Francisco Examiner