Other Worlds | Page 2

and only such knowledge
of the starry heavens as anybody can easily acquire.
G.P.S.
BOROUGH OF BROOKLYN, NEW YORK CITY, September, 1901.

CONTENTS
CHAPTER I
INTRODUCTORY 1
Remarkable popular interest in questions concerning other worlds and
their inhabitants--Theories of interplanetary communication--The
plurality of worlds in literature--Romances of foreign
planets--Scientific interest in the subject--Opposing views based on
telescopic and spectroscopic revelations--Changes of
opinion--Desirability of a popular presentation of the latest facts--The
natural tendency to regard other planets as habitable--Some of the
conditions and limitations of the problem--The solar system viewed
from outer space--The resemblances and contrasts of its various
planets--Three planetary groups recognized--The family character of
the solar system
CHAPTER II
MERCURY, A WORLD OF TWO FACES AND MANY CONTRASTS 18

Grotesqueness of Mercury considered as a world--Its dimensions, mass,
and movements--The question of an atmosphere--Mercury's visibility
from the earth--Its eccentric orbit, and rapid changes of distance from
the sun--Momentous consequences of these peculiarities--A virtual fall
of fourteen million miles toward the sun in six weeks--The tremendous
heat poured upon Mercury and its great variations--The little planet's
singular manner of rotation on its axis--Schiaparelli's astonishing
discovery--A day side and a night side--Interesting effects of
libration--The heavens as viewed from Mercury--Can it support life?
CHAPTER III
VENUS, THE TWIN OF THE EARTH 46
A planet that matches ours in size--Its beauty in the sky--Remarkable
circularity of its orbit--Probable absence of seasons and stable
conditions of temperature and weather on Venus--Its dense and
abundant atmosphere--Seeing the atmosphere of Venus from the
earth--Is the real face of the planet hidden under an atmospheric
veil?--Conditions of habitability--All planetary life need not be of the
terrestrial type--The limit fixed by destructive temperature--Importance
of air and water in the problem--Reasons why Venus may be a more
agreeable abode than the earth--Splendor of our globe as seen from
Venus--What astronomers on Venus might learn about the earth--A
serious question raised--Does Venus, like Mercury, rotate but once in
the course of a revolution about the sun?--Reasons for and against that
view
CHAPTER IV
MARS, A WORLD MORE ADVANCED THAN OURS 85
Resemblances between Mars and the earth--Its seasons and its white
polar caps--Peculiar surface markings--Schiaparelli's discovery of the
canals--His description of their appearance and of their
duplication--Influence of the seasons on the aspect of the canals--What
are the canals?--Mr. Lowell's observations--The theory of

irrigation--How the inhabitants of Mars are supposed to have taken
advantage of the annual accession of water supplied by the melting of
the polar caps--Wonderful details shown in charts of Mars--Curious
effects that may follow from the small force of gravity on
Mars--Imaginary giants--Reasons for thinking that Mars may be, in an
evolutionary sense, older than the earth--Speculations about
interplanetary signals from Mars, and their origin--Mars's
atmosphere--The question of water--The problem of
temperature--Eccentricities of Mars's moons
CHAPTER V
THE ASTEROIDS, A FAMILY OF DWARF WORLDS 129
Only four asteroids large enough to be measured--Remarkable
differences in their brightness irrespective of size--Their widely
scattered and intermixed orbits--Eccentric orbit of Eros--the nearest
celestial body to the earth except the moon--Its existence recorded by
photography before it was discovered--Its great and rapid fluctuations
in light, and the curious hypotheses based upon them--Is it a fragment
of an exploded planet?--The startling theory of Olbers as to the origin
of the asteroids revived--Curious results of the slight force of gravity
on an asteroid--An imaginary visit to a world only twelve miles in
diameter
CHAPTER VI
JUPITER, THE GREATEST OF KNOWN WORLDS 160
Jupiter compared with our globe--His swift rotation on his
axis--Remarkable lack of density--The force of gravity on
Jupiter--Wonderful clouds--Strange phenomena of the great
belts--Brilliant display of colors--The great red spot and the many
theories it has given rise to--Curious facts about the varying rates of
rotation of the huge planet's surface--The theory of a hidden world in
Jupiter--When Jupiter was a companion star to the sun--The miracle of
world-making before our eyes--Are Jupiter's satellites

habitable?--Magnificent spectacles in the Jovian system
CHAPTER VII
SATURN, A PRODIGY AMONG PLANETS 185
The wonder of the great rings--Saturn's great distance and long
year--The least dense of all the planets--It would float in water--What
kind of a world is it?--Sir Humphry Davy's imaginary inhabitants of
Saturn--Facts about the rings, which are a phenomenon unparalleled in
the visible universe--The surprising nature of the rings, as revealed by
mathematics and the spectroscope--The question of their origin and
ultimate fate--Dr. Dick's idea of their habitability--Swedenborg's
curious description of the appearance of the rings from Saturn--Is
Saturn a globe of vapor, or of dust?--The nine satellites and "Roche's
limit"--The play of spectacular shadows in the Saturnian
system--Uranus and Neptune--Is there a yet undiscovered planet greater
than Jupiter?
CHAPTER VIII
THE MOON, CHILD OF THE EARTH AND THE SUN 212
The moon a favorite subject for intellectual speculation--Its nearness to
the earth graphically illustrated--Ideas of the ancients--Galileo's
discoveries--What first raised a