Page:Popular Science Monthly Volume 1.djvu/303

Rh But we are thus led to consider a circumstance which, as it appears to us, disposes finally of the idea that in the cloud-rings of Jupiter we have to deal with phenomena resembling those presented by our own earth.

We are too apt, in studying the celestial objects, to forget that where all seems at nearly perfect rest, there may be processes of the utmost activity—nay, rather, of the utmost violence—taking place as it were under our very eyes, and yet not perceptible save to the eye of reason. Looking at Jupiter, under his ordinary aspect, even in the finest telescope, one would feel certain that a general calm prevailed over his mighty globe. The steadfast equatorial ring, and the straight and sharply-defined bands over either hemisphere, suggest certainly no idea of violent action. And when some feature in a belt is seen to change slowly in figure—or, rather, when at the end of a certain time it is found to have so changed, for no eye can follow such changes as they proceed—we are not prepared to recognize in the process the evidence of disturbances compared with which the fiercest hurricanes that have ever raged on earth are as mere summer zephyrs.

Indeed, the planet Jupiter has been selected even by astronomers of repute as an abode of pleasantness, a sort of paradise among the planet-worlds. There exists, we are told, in that distant world, a perennial spring—"a striking display of the beneficence of the Creator," says Admiral Smyth; "for the Jovian year contains twelve mundane years; and, if there were a proportionate length of winter, that cold season would be three of the earthly years in length and tend to the destruction of vegetable life."

Even those who have denied that Jupiter can be the abode of life, and have formed altogether unfavorable ideas of his condition, have pictured him nevertheless as the scene of continual calm, though the calm is, according to their view, the calm of gloom and desolation. They recognize in Jupiter an eternal winter rather than a perpetual spring. Whewell, for example, in that once famous work the "Plurality of Worlds," maintained that, if living creatures exist at all in Jupiter, they must be wretched gelatinous monsters, languidly floating about in icy seas. According to him, Jupiter is but a great globe of ice and water, with perhaps a cindery nucleus—a glacial planet, with no more vitality in it than an iceberg.

But when we begin to examine the records of observers, and to consider them with due reference to the vast proportions of the planet, we recognize the fact that, whatever may be Jupiter's unfitness to be the abode of life, it is not of an excess of stillness that his inhabitants (if he have any) can justly make complaint. Setting aside the enormous activity of which the mere existence of the belts affords evidence, and even regarding such phenomena as the formation or a disappearance of a new belt in two or three hours as merely indicative of heavy rainfalls or of the condensation of large masses of invisible