Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1907-11-11
NEWS OF THE NEIGHBORS

onds and, as one can easily reckon,
makes something more than 366 revo-
lutions in year. .
But human beings are not SO much
interested in the stars as in the sun.
We really don't care much how long it
takes the earth to turn over and bring
star back again to the same point i'll
the sky or how many times In a year
star seems to go by. We set our
clocks and reckon our year by the
turning of the earth under the sun,
and because the earth not only turns
under the sun, but also goes round it,
1t takes about four minutes longer to
! bring the sun up to its old place in
the sky Than to bring back a star This
comes about simply enough. Suppose
one is in a room looking out the win
| dow at tree. If he turns round once
exactly he will find himself looking
tried the same thing when he was on
moving train he would find that
while be was making the turn the tree
! had fallen behind. He would then, ac-
cOrding to the way he twirled, have to
turn little more or little less to
bring the tree straight before his nose.
| Therefore it is not quite true that Il
day is the time required for the earth
to turn once on it's axis. 1t really is
this time plus the four minutes or so
required for it to turn and look back
at the sun. The time required for this
extra turn is not the same at all times
in the year. One can easily see in the
case of the moving train that the fast
er the ears We're moving or the nearer
the track the tree stood the more the
latter would seem to shift its position.
Since the earth is some 100000 miles
nearer the sun in winter than in sum
mer, and since also the nearer the sun
it is the faster it travels, the difference
between star day and sun day is
greatest in winter.
Oddly enough, it happens that Dec.
% which has the least daylight Of
any day in the year and is therefore
commonly said to be the shortest of
nj! days, is really the longest. 1t does,
as n matter of fact, run almost half Il
minute over twentyfour hours, while
the true shortest day, which comes on
Sept II, falls short by about the same
time.
SO we really have three different
days" There is the star day, which
is the time during which the earth
turns over once. This, because the
earth spins steadily, is always the
same length, twenty-three hours. fifty
. six minutes. four and nine-hundredthS
seconds, and there are $3.50 of them in
n year. Then there is the ordinary le-
gal day, which is the time required for
a proper clock to get round twice
This is just twenty-four hours. Be.
sides these, there is the sun day its
time told by the Sundial, which, tax
! ing short with long, averages twenty
: four hours, but is never found to be
t exactly the same length for two days
in succession.
There is string of long days in tile
1 winter, followed by Il series of short
ones in the spring In the summer the
= sun days get long again, though not
: quite so long as in the winter In the
p autumn come the shortest days of all
t Only occasionally are clock day anC
= sun day of the same length. Only
: four times Il year do clock noon b!
,, the clock hands and sun noon by tn,
5 sundial occur at the same moment
while, because the long and short SUI
i days are found in sets, they oftentime:
!, may be more than fifteen MINUTES
8 apart.
e The vast majority of the people
= reckon their time by the sun. Blu
q time for civilized men is time by tn,
Il clock. The days are ali twenty-fou
/ hours long, and no matter where tn
h sun is it is noon for us, when the clocl
T. strikes II. Nevertheless, astronomer
: often go by star time, get in an eXtr;
:. "A" in each year and have their nool
iTil at all times of the day or night
f. T. Brewster in Chicago Record Her
aid.