s part of the galaxy, but on the
contrary good ground for considering that he belongs to the class of
insulated stars, few of which have shown signs of irregular variation,
while none have ever blazed suddenly out with many hundred times their
former lustre, we may fairly infer a very high degree of probability in
favour of the belief that, for many ages still to come, the sun will
continue steadily to discharge his duties as fire, light, and life of
the solar system.

VII.

_THE RINGS OF SATURN._

The rings of Saturn, always among the most interesting objects of
astronomical research, have recently been subjected to close scrutiny
under high telescopic powers by Mr. Trouvelot, of the Harvard
Observatory, Cambridge, U.S. The results which he has obtained afford
very significant evidence respecting these strange appendages, and even
throw some degree of light on the subject of cosmical evolution. The
present time, when Saturn is the ruling planet of the night, seems
favourable for giving a brief account of recent speculations respecting
the Saturnian ring-system, especially as the observations of Mr.
Trouvelot appear to remove all doubt as to the true nature of the rings,
if indeed any doubt could reasonably be entertained after the
investigations made by European and American astronomers when the dark
inner ring had but recently been recognised.

It may be well to give a brief account of the progress of observation
from the time when the rings were first discovered.

In passing, I may remark that the failure of Galileo to ascertain the
real shape of these appendages has always seemed to me to afford
striking evidence of the importance of careful reasoning upon all
observations whose actual significance is not at once apparent. If
Galileo had been thus careful to analyse his observations of Saturn, he
could not have failed to ascertain their real meaning. He had seen the
planet apparently attended by two large satellites, one on either side,
'as though supporting the aged Saturn upon his slow course around the
sun.' Night after night he had seen these attendants, always similarly
placed, one on either side of the planet, and at equal distances from
it. Then in 1612 he had again examined the planet, and lo, the
attendants had vanished, 'as though Saturn had been at his old tricks,
and had devoured his children.' But after a while the attendant orbs had
reappeared in their former positions, had seemed slowly