The Ottawa free trader. [volume] (Ottawa, Ill.) 1843-1916, 1877-12-01

The sun Is 10 us the most important OF inc
celestial bodies. 1t seems to be the largcS. and
the most brilliant and the one which eXertS
the most perceptblc influence on our globe.
The center OF motion for our planet and lis
lneiphbors, it is also the source from which
come the light and heat so essential to life.
Ii certainly exercises an influence on the
magnetic and electric condition OF our planet,
but to what extent is still subject for invest.
CATION.
To the naked eve the brillianCy of the sun
is unbeatable We can look at the moon, how
ever, without inconvenience; and one would
imagine we might, when it is known that the
suns rays exert Il force equal to eight hundred
thousand times of the full moon or, to compare
with the stars, twenty-five billion times that
of the brightest star. In order, then, to look
at it, some colorcd glass Is usually interposed
before the eye, and by this means the danger
is much lessened
In figure it is spherical, and appears to lis
as n circular disk. If there is any tlattening at
the poles. 1t is so small as TO escape measure
mcnt, and this need not seem strange since the
light is so strong that only at rare times is the
disk border clearly seen 1t has a revolution
around an axis, as Is easily shown by the path
of the solar spots across the disk. In the
morning at sunrise and in the evening at sun
set the disk appears very Sensiby tiattened
| but this is an optical illusion, Is exact meas.
urement easily shows.
Probably but few have noticed the fact that
the sun appears slightly larger at certain sea
sons of the year than at Others. This is the
case owing TO our planets being nearer the sun
at one scason-winter-that at another season
summer The apparent diameter of the sun
at the former time is little over thirty-two
and "A half minutes, AT the latter time little
more than thirty-o one and half minutes dill
ference of about one-thirtieth.
| The distance of the sun from Us varies then
with different seasons of the year, being, u
stated above, nearer in winter than IN summer
but the average distance is about 90 100000 OF
miles. Former calculations made the distance
900 900 more than this, but they were incor
rect The results obtained from the transit Of
Venus have not been published yet, but prob
ably not very much change in the distance will
be made. The ancientS held livery vague notions
concerning the distance of the sun. Arlstarch
us of Samos supposed it to be about 100000
of miles; Kepler tripled that number; Cossin
asserted that il was about 200O00O00, but fin
ally settled on distance about equal TO thai
now used.
IL is difficult TO obtain any clear idea of thi,
distance, although il is very small, astronomi
cally speaking. To assist 10 comprehension
let us consider that light travels about one hun
dred and eighty-iive Thousand miles per second
vet requires over eight minutes TO come to The
earth from the SUM- sound would require four
teen years, and u railroad express train would
reach the sun from us in the year aa24. littlC
over three hundred and iorty-seven years aitel
its departure.
| This distance 80 vast rs il seems is the uni
ON which other astronomical distances ar,
based. Ifthis seems large how must the dis
lance of the stars seem, from the nearest q
which light requires three years, and from
some of them thousands of years are necessary
so that on looking through our telescopes a
them We do not see them as they are 10 day
but as they were thousands OF years ago. year
before the universe was created, according e
the old idea Herman Poole