If there be such a thing as Jovian life, that is to say, if there are any inhabitants on Jupiter, the following are the advantages they obtain by living on the great planet—advantages so poetically brought into relief at the memorable meeting above alluded to.
In the first place, during the diurnal rotation of Jupiter, which occupies nine hours, fifty-five minutes, the days are always equal to the nights in all latitudes; that is to say, the Jovian day is four hours, fifty-seven minutes long, and the Jovian night lasts also four hours and fifty-seven minutes.
“There,” said the admirers of Jovian existence, “you have something suited to people of regular habits. They will be delighted to submit to such regularity.”
That is what would happen to the Earth if Barbicane did what he promised, only as the new axis would make no difference in the time of rotation, twenty-four hours would still separate the successive noons, and our spheroid would be blessed with nights and days each twelve hours long, and we should live in a perpetual equinox.
“But the climatal phenomena would be much more curious; and no less interesting,” said the enthusiasts, “would be the absence of the seasons.”
Owing to the inclination of the axis to the plane of the orbit, we have the annual changes known as spring, summer, autumn, and winter. The Jovians could know nothing of these things, and the Terrestrians would know them no more. The moment the new axis became perpendicular to the ecliptic there would be neither frigid zones nor torrid zones, but the whole Earth would rejoice in a temperate climate.
Why was this?
What is the Torrid zone? It is that part of the Earth comprised between the Tropics of Cancer and Capricorn. Every place within this zone has the Sun in the zenith twice a year.
What are the Temperate zones? The part comprised between the Tropics and the Polar circles; between 23° 28′ and 66° 32′ of latitude, and in which the Sun never rises to the zenith, but is above the horizon on every day in the year.
What are the Frigid zones? That part of the circumpolar regions in which the Sun does not rise above the horizon on every day in the year; while at the Pole itself he does not rise for six months at a time.