Deseret evening news. [volume] (Great Salt Lake City [Utah]) 1867-1920, 1892-02-05
POINTS ABOUT TIME.
VARIATIONS AND THE CAUSES WHICH
PRODUCE THEM.

-he Earih's Revolution. on 1t. ASiA, To-
gethor with Its Journey Around tho
Sun, Are the Disturbing raotors-No
watch l. Perfectly Reliable.
II there Is one single scientific problem
upon which moro than another people
appear to get mixed that problem Is
time. Standard time, local time. sun
time are exceedingly difficult problems
for tho public to puzzle over, and when
sidoreal time enters the calculation the
case Ia hopeless indeed. have fire.
qucntly Of lato seen so many lcttors adj
dressed this and other journals, all
touching upon one or tho other Of these
chronological questions, that have con.
cluded n short noto explaining tho main
points Of difference would be, at any
rate, timely. II 1t only suggests to tho
young men In tho business offices the
idea Of going to work at pa. m. local
mean time, and leaving oil promptly at
Up. IN, Pacific standard time, the ques-
ton will hnvo boon shown to possess n
practical side. Tho application Of 1t,
however, Is purely a matter Of taste.
Wen. 10 come 10 timo, the great chro.
nomotcr and regulator In chief 10 the
business, social and scientific world is the
oarthitself. Turning upon lis axis In the
period which we divide into twonty.foui
hours, the sun appears to cross the me.
ridian of each place on tho globe once IN
that interval. The moment at which IL
crosses the meridian Of any place (Greon'
wich), for example, is termed "local ~
parent noon" ut that place This would
DO all very well II tho earth and sun r.
manned tixod in their relative positions
or II tho Garth, completing, ~ It does, an
annual revolution about the sun, did 80
uniformly in u perfect circle aud that
circle were In tho same plano with Tho
motion Of daily rotation. Thon the sue
cessive intervals between tho meridian
passages Of tho sun ut Greenwich would
all be equal, and perfect ohronomctci
set at ~ hrs., o min, D Sec, whom the
sun transited today would indicate pro
oisely tho same instant for "apparen,
noon" at every date
MOTIONS or TIE EARTH.
But the oarth's path around tho sun {,
not a perfect circle; II Is an ollipso, and
tho motion In ono portion Of the ellipso T.
moro rapid than In another, and thi,
causes a slight variation in tho interval
between the solar passages. Again, n,
plane OF tho earth's path around the sun
or tho elliptic, IA inclined esq dcga C
the plano Of tho equator In which III,
daily rotation takes place, and conse
qucntly twice year tho intervals o.
apparent noon" are each about twenty
seconds greater and. twice year about
twenty seconds less thnn twenty-foui
hours, To explain just why this results
would require more Of IN investigation
into astronomical principles than "a hort
contemplated; bnt It is 40, nevertheless,
and any text book will olucidate tho rca
sons, A combination OF tho two effect
causes the sun TO be apparently slow
fourteen minutes in February and fU'
sixteen minutes In November, But IL
the course Of year tho average come,
ont all right, and therefore n linear
solar day" Of exactly twenty-four hour
Is adopted In the almanao5 and used foi
all purposes. This accounts for tho diff
ference between mean time and sun time
A regulator keeps the former; sun din
indicates tho latter,
A few years ago Tor prior to 1880 every
large city in tho United States had ~
own local time. and this was for eacl
place tho true mean solar time, obtainel
rs above indicated.
REGULATING TIME.
Consequently, a man travelling west
ward from Washington would find hi
watch fast, as follows; At Chicago, 4,
minutes at Omaha, hour 10 minutes
at Denver, | hour % minutes; at Sal
Lake City, hours 20 minutes, and final
ly, at San Francisco, 3 hours minutes
1t will readily DO recalled how mucl
annoyance was occasioned by all thosl
various corrections, both to trainmui
and travellers. About tho year men
toned great reform was inaugureted
Nowadays u traveller going WESTWARD
finds his watch fast from time TO time
but only the hour hand Is in error. Al
the clocks in tho country indicate Tia,
minute and second Of Greenwich meaI
time, but tho hour is changed for oacl
10 dogs. Of longitude. Washington tint
Is s hours slow Of Greenwich; Chicago
o hours; Denver, hours. In San Fran
ciHuAa xun ara X lnttf5. slnxu nf tla ,,pi,r,