The Spokane press. [volume] (Spokane, Wash.) 1902-1939, 1907-01-16

MY experience III SHOWING more
than 10000 visitors through the
great Lick telescope, on the Satur
day evening of nine years, led me
to the conclusion, confirmed agar
and again, that, while substantially
everybody is eager to acquire as
Economical knowledge, yet the fun
damental facts of the science are
known to comparatively few. Fol
example, a small majority could tel
me the difference between a planet
and a star, but those who had q
fair comprehension of the solar
system were rare indeed
A subject grander than the solar
system would be difficult to find
and, as it Is also the natural start
ing point in the study of astronomy
I shall hope so to describe it that
all who read with care will have q
good idea of the system and of its
relation to other celestial systems
The sun is one of the ordinary
stars, comparable in size and sub
stance with the 100,000,000 other
stars visible in our telescopes. II
seems larger and brighter and hot
ter than other stars because we are
relatively so very close to it, The
earth is member of its family
The suns stupendous gravitationa
power compels the eight major
planets-Mercury Venus, Earth
Mars. Jupiter, Saturn, Uranus, Nep
tune-and the many hundreds OF
minor planets, to revolve around
it, at various distances, in orbits
nearly circular,
We are accustomed to regard the
earth as fairly large body. In
comparison with just the small
structures of the universe how
puny are the works of man, A
mighty nation must labor 10 years
to cut ships channel through the
little ridge at Panama, which rises
only 400 feet above the sea. Now
the sun is so vast that If it were
q hollow shell of the same size
more than a million earths could
be poured into it and the spaces
between the balls would still re-
main unoccupied.
The average distance of the earth
from the sun is 100000 miles
An express train running so miles
per hour, day after day, and year
after year, without making stop,
would require 210 years to carry a
celestial passenger from one body
to the other. The outermost planet
of the system, Neptune, is 80 times
as far from the sun as we are, and
the nearest star Is 5000 times as
far away as Neptune. These dis
tances are too great for human
comprehension. Let us sketch the
suns family on miniature scale
Near the center Of large sheet
of paper make an exceedingly small
dot to represent the sun. With this
as a center draw a faint circle, one
half inch radius, to represent the
orbit in which the earth, accom-
tpanied by its moon--our moon-re
wolves around the sun one pei
year. On the same scale, circle
of radius one-fifth of an inch Is ap
proximately the orbit in which
Mercury completes a revolution ii
8S days. The corresponding Orbit
of Venus, period 225 days, will be
of radius three-eighths OF an inch
Beyond the earth's orbit draw 6
circle of radius three-fourths of al
inch. which Mars. with his two
diminutive moons, follows once
around in 6S7 days. Draw another
circle of two and five-eighths inches
radius for Jupiter and his seven
moons. His period of revolution Is
a little less than II years. In the
broad space between Mars ant
Jupiter, more than 600 small plan
cts, or asteroids, are moving In {
great variety of elliptic orbits
whose periods Of revolution vary
from less than two to more thar
eight years. These asteroids are
so tiny that. If they were all united
In one body, 1t would be much
Smaller than the earth. Next. draw
q circle Of radius four and three
fourths inches for Saturn, his won
derful ring system and his II
moons. The period of Saturn is
1914 years. Let another circle be
drawn with radius nine and five
eighths inches as the orbit of Uran
ns and his four moons. His period