398
■observations have not supported his conclusion, nor have theyrevealed any other decided physical features. Some traces ofa belt were at one time supposed to be seen upon it, but thiswas exceedingly doubtful; while the suspicion of the existenceof a ring surrounding it, similar to those of Saturn , has beenquite given up.
In 1870 and 1872 Mr. Buffham, observing in Bonner’s Road,Victoria Park, with a 9-inch mirror by With, thought that he■detected a rotation of the planet upon its axis in about 12hours, from the motion of certain spots, or portions of a belt,upon its surface; but since that date, so far as we are aware, no■other observer has confirmed his statement.
It is useless to discuss the habitability of Uranus , and veryhard to conceive its possibility. We may, however, remark that,if any inhabitants could exist upon it, they might, at intervals■of nearly fifteen years, see Saturn at its greatest elongationfrom the Sun as a morning or evening star. But, even when■so seen, its light would only amount to about T hth part* ofthat which it exhibits to the Earth when most favourablysituated iu Opposition.
On the other hand, Neptune would be far better seen whennear to Opposition than from the Earth , and might shine with■seven times as much light. It is just possible that Jupiter might be detected by a very careful scrutiny, even as Mercuryis with difficulty seen by us ; but Mars and the Earth , and allthe other planets, would always be much too near to the Sun to be visible.
So remote is the planet Uranus that the intensity of lightand heat which it receives from the Sun is only equal to about-j^tli of that which the Earth enjoys. That same remoteness
* Saturn , in the two cases referred to, would be at distances fromUranus and the Earth respectively, of which the former would be fully
times as great as the latter. In the former case its phase would alsobe only that of a half-moon, in place of the fully illuminated disc which itshows to the Earth when in Opposition. The increase of distance woulddiminish its light in the ratio of the square of that distance, or betweenfive and six times; and the half-moon phase would further reduce it byone-half; or to about rVth of that which we see under the most favourablecircumstances.