The San Juan islander. [volume] (Friday Harbor, Wash.) 1898-1914, 1911-10-13
TINE BY mERIDIANs
ARRANGEMENT THAT MAkea
The COMMON sTANpARo.
System patss From 1883, and VS.
Devised 70 Meet the Require
msnts Of the Railroads
Explanation 10 Simple.

The measure Of any circle. includ.
Ing the circumference Of the earth, az
course. 10 $50 degrees. The earth re-
wolves on its axis once in "a hours:
hence the sun appears to pass over
one-twenty-fourth Of the circumfer.
ence Of the earth In one hour. Il IL
always noon at some point on the
earth's surface. and Of course at
point halfway around the earth. It II
midnight The extension OF the rail-
way systems Of the United States,
which cover nearly go degrees Of
longitude. caused all kinds Of trouble
because of the difference Of time. It
10 noon by the sun at any point on
the earth's surface when the sun IL
directly over the meridian Of that
point-that is. 1t is noon by sun time:
but nobody runs by sun time. Why?
Because the movement Of the earth
In Its orbit Is faster in winter than
In summer: 80 that the time common
" called sun time" at each city, II
not sun time. as measured by the
minute the sun reaches the meridian
OF that point: but. what is called
mean time" which 10 the average
time throughout the year that the
sun would be on the meridian II the
motion Of the earth were absolutely
equal at all points in its orbit.
The more the railway business Of
the country increased, the greater be-
came the trouble. So, in 1883. the
system called standard time" was do
vised and adopted by all the railroads
In the United States. The plan-and
a remarkably wise one-was to des-
tgnate certain meridians. Il degrees
apart-and where the difference In
actual sun time would. Of course. be
exactly one hour-and have the time
be the same for space Of country.
OF which these meridians should be
the middle.
The first meridian is that of Is de-
grees west Of Greenwich. This line
passes just east of Philadelphia. For
seven and one-half degrees east and
west Of this. the railroads keep what
Is known as eastern time" The
next meridian is that of 30 degrees
west Of Greenwich. which passes
through Wisconsin. eastern Iowa and
close to Memphis. This Is called
central time" The next is the
space, IL degrees wide. Of which the
meridian Of los degrees west of
Greenwich Is the middle. That merid-
Ian passes through the eastern edges
on Montana and Wyoming. and just
west Of Denver. This 10 called
mountain time" The next time-strip
has its middle on the meridian Of
120 degrees west Of Greenwich. which
passes through Washington, Oregon
and California. This IL called "Paci-
DC time"
For instance. suppose one 10 travel
ing from San Francisco east. and sets
his watch In that city. Suppose he
comes east over the Union Pacific. At
Ogden. which the railroad has made
the point Of timedivision, he sets his
watch an hour faster. At Cheyenne
Mills. Colo. he sets 1t an hour faster
again. for the changes from mountain
to central time. He reaches Chicago.
and goes east over the Lake Shore.
At Buffalo he sets his watch one hour
faster, that being the dividing point
between central and eastern. time.
When he does this he nnds his watch
agreeing with the time of the places
through which he passes. and With
the railway timecards. II he travelled
westward. he would simply set his
watch one hour slower at the point
named.