XXII. Observations and remarks on the figure, the climate, and the atmosphere of Saturn, and its ring. By William Herschel, LL. D. F. R. S

Abstract

My last year’s observations on the singular figure of Saturn having drawn the attention of astronomers to this subject, it may be easily supposed that a farther invesigation of it will be necessary. We see this planet in the course of its revolu­tion round the sun in so many various aspects, that the change occasioned by the different situations in which it is viewed, as far as relates to the ring, has long ago been noticed; and Huygens has given us a very full explanation of the cause of these changes.* As the axis of the planet’s equator, as well as that of the ring, keeps its parallelism during the time of its revolution about the sun, it follows that the same change of situation, by which the ring is affected, must also produce similar altera­tions in the appearance of the planet; but since the shape of Saturn, though not strictly spherical, is very different from that of the ring, the changes occasioned by its different aspects will be so minute that only they can expect to per­ceive them who have been in the habit of seeing very small objects, and are furnished with instruments that will show them distinctly, with a very high and luminous magnifying power.