A Journey in Other Worlds | Page 8

case the sun's rays are caused to shine more perpendicularly,
and in the other more obliquely. This wabbling, like that of a top, is the sole cause of the
seasons; since, owing to the eccentricity of our orbit, the earth is actually fifteen hundred
thousand miles nearer the sun during our winter, in the northern hemisphere, than in
summer. That there is no limit to a planet's inclination, and that inclination is not essential,
we have astronomical proof. Venus's axis is inclined to the plane of her orbit seventy-five
degrees, so that the arctic circle comes within fifteen degrees of the equator, and the
tropics also extend to latitude seventy-five degrees, or within fifteen degrees of the poles,
producing great extremes of heat and cold.
"Venus is made still more difficult of habitation by the fact that she rotates on her axis in
the same time that she revolves about the sun, in the same way that the moon does about
the earth, so that one side must be perpetually frozen while the other is parched.
"In Uranus we see the axis tilted still further, so that the arctic circle descends to the
equator. The most varied climate must therefore prevail during its year, whose length
exceeds eighty-one of ours.
The axis of Mars is inclined about twenty-eight and two thirds degrees to the plane of its
orbit; consequently its seasons must be very similar to ours, the extremes of heat and cold
being somewhat greater.
"In Jupiter we have an illustration of a planet whose axis is almost at right angles to the
plane of its orbit, being inclined but about a degree and a half. The hypothetical
inhabitants of this majestic planet must therefore have perpetual summer at the equator,
eternal winter at the poles, and in the temperate regions everlasting spring. On account of
the straightness of the axis, however, even the polar inhabitants--if there are any--are not
oppressed by a six months' night, for all except those at the VERY pole have a sunrise
and a sunset every ten hours--the exact day being nine hours, fifty five minutes, and
twenty-eight seconds. The warmth of the tropics is also tempered by the high winds that
must result from the rapid whirl on its axis, every object at the equator being carried
around by this at the rate of 27,600 miles an hour, or over three thousand miles farther
than the earth's equator moves in twenty-four hours.
"The inclination of the axis of our own planet has also frequently considerably exceeded
that of Mars, and again has been but little greater than Jupiter's at least, this is by all odds
the most reasonable explanation of the numerous Glacial periods through which our
globe has passed, and of the recurring mild spells, probably lasting thousands of years, in

which elephants, mastodons, and other semi-tropical vertebrates roamed in Siberia, some
of which died so recently that their flesh, preserved by the cold, has been devoured by the
dogs of modern explorers.
"It is not to be supposed that the inclining of the axes of Jupiter, Venus, the Earth, and the
other planets, is now fixed; in some cases it is known to be changing. As long ago as
1890, Major-Gen. A. W. Drayson, of the British Army, showed, in a work entitled
Untrodden Ground in Astronomy and Geology, that, as a result of the second rotation of
the earth, the inclination of its axis was changing, it having been 23@ 28' 23" on January
1, 1750, 23@ 27' 55.3" on January 1, 1800, and 23@ 27' 30.9" on January 1, 1850; and
by calculation one hundred and ten years ago showed that in 1900 (one hundred years
ago) it would be 23@ 27' 08.8". This natural straightening is, of course, going on, and we
are merely about to anticipate it. When this improvement was mooted, all agreed that the
EXTREMES of heat and cold could well be spared. 'Balance those of summer against
those of winter by partially straightening the axis; reduce the inclination from
twenty-three degrees, thirty minutes, to about fifteen degrees, but let us stop there,' many
said. Before we had gone far, however, we found it would be best to make the work
complete. This will reclaim and make productive the vast areas of Siberia and the
northern part of this continent, and will do much for the antarctic regions; but there will
still be change in temperature; a wind blowing towards the equator will always be colder
than one blowing from it, while the slight eccentricity of the orbit will supply enough
change to awaken recollections of seasons in our eternal spring.
"The way to accomplish this is to increase the weight of the pole leaving the sun, by
increasing the amount of material there for the