Saturn Planet

,Saturn was recognised as a planet by the ancients, and was the outside member of the solar system as known by them. So far from the sun is he that 29-1/2 years are spent by him in going once round his celestial path. His orbit is about 2-1/2° from the elliptic, and is an ellipse differing considerably from a circle, his greatest distance from the sun being about 921,000,000 and his least about 823,000,000 miles. His diameters at the equator and poles differ considerably, the protuberance at the equator giving him there a diameter of 74,000 miles, while at the poles it is only 68,000. His rota~ tion about his own axis is very rapid, taking about 10-1/2 hours, a number slightly exceeding that of Jupiter, while the plane of his equator makes an angle of about 27° with the plane of his orbit. In size Saturn is the largest of the planets except Jupiter, being in fact 700 times larger than our earth, but his density is so small that he would be able to float on water far more easily than an iceberg. From this it follows that he cannot consist of solid or liquid matter, and in fact we can only view a mass of clouds intensely heated within, the whole being probably a planet in the early stage of development - younger even than Jupiter. The most remarkable characteristic of Saturn, which makes him an object of such interest in the sky, is his possession of a luminous ring. This was originally discovered by Galileo, who first thought that the planet was merely attended by two other bodies, one on each side of it, these two objects gradually fading away till the planet appeared alone, but later on reappearing. Their true nature was afterwards explained by Huyghens, who showed that these changes could be accounted for by a thin opaque circular ring surrounding the planet's equator, though at some distance away,and accompanying the planet on his travels. The ring is only luminous on account of its reflection of the sun's light; hence will be invisible to us when, for instance, we are endeavouring to look at the ring from below while the sun is shining above. It also sometimes happens that the plane of the rings passes through the sun or through the centre of the earth, in which case only the thin edge of the rings can be seen at all; unless then a powerful telescope is being used, nothing will be visible. Cassini, in 1675, showed that the ring was divided into two parts, the inner being the wider, and 1ater another faint division appeared to divide the outer part into two smaller nngs. In 1850 another ring was discovered by Professor Bond in America and Mr. Dawes in England; this is quite different. from the outer rings, being dark, and generally known as the dusky ring of Saturn. The outer ones, though far from solid, can receive a shadow of Saturn, and themselves cast one on his disc. The dusky ring can do nothing of the kind, and its filmy nature doubtless prevented its earlier discovery. That the rings must rotate about the planet is necessary for their existence, and Sir William Herschell demonstrated that they actually did so by observing the motion of tiny spots of light. upon them. Clerk Maxwell demonstrated that the rings are not continuous masses of matter, but consist of countless myriads of tiny satellites, so close together that to us they appear as one body. From observations made over a considerable period, it seems that the inner edge of the bright ring is gradually approaching the planet, while the outer edge of all is getting farther away, thus increasing the breadth of the bright rings. The planet has 8 satellites [SATELLITES], which seldom pass behind or in front of the planet's disc, and therefore are not objects of great interest. In 1899 the discovery of a ninth satellite was announced.