50 Traxsactioxs of the American Institute. 



nioments ago. Mars has an atmosphere and, strange to say, he has a 

 year two years long. When one of the poles comes out of that long 

 winter of a whole year's duration, some how or other it is all clothed 

 in white ; and when it is exposed to the sunshine long enough, that 

 white appearance is gone again. How like it looks to a formation of 

 enow and ice on the earth, whether the same sort of material or not. 

 But Mars has moisture in his atmosphere, and why may not, there- 

 fore, the acci-etion be exceedingly like that on the Earth? So far,, 

 then, for what the telescope tells us. Huygens made use of a telescope 

 of full twenty-three feet in length and four inches aperture {i. «., 

 diameter of object glass), which he reduced to tM'o and one-eighth 

 inches. He also discovered a satellite to Saturn. In 1671 Cassini 

 discovered another satellite, and afterward three more. He also 

 perceived the ring of Saturn to be double, soon after his establishment 

 at the Observatory of Paris in 1675. It seems, however, that he waa 

 anticipated in this discovery by two English amateurs. Dr. Ball and 

 Mr. W. Ball, about ten years. The ring of Saturn ; Oh, what a 

 mysterious affair. It is a substajiUa singularis, as Lord Bacon would 

 say, in the solar system. Not merely is Saturn bent like Jupiter, 

 and therefore the belts show the same curvature, but he is surrounded 

 by a whole system of rings, and when the state of things under which 

 those rings exist is carefully considered, it is found that they must be 

 either liquid or else formed of a great number of small bodies, all 

 floating together. The phenomena will agree quite as well as any- 

 thing with a great liquid steam, which would be about the distance 

 from the planet equal to two-thirds of the distance between the earth 

 and the moon, and yet would be forty miles thick, sustained inces- 

 santly by the beautiful balance of forces as the stream goes around 

 Saturn ; for the satellites of Saturn and Jupiter, and our own moon, 

 are always flung around so fast that they never fall, and Saturn is 

 always kept inside, in the middle, by the agitation of his enormous 

 satellites on the outside, very much as a balance of skill by slight 

 agitations of the end of a rod will keep it constantly perpendicular. 

 He could not have the ring a moment unless his satellites were on 

 the outside — veritable satellites or guardians of his ring, so that 

 he may not lose it. The next thing I shall speak of noticed bj 

 the telescope is the fixed stars, but before I quite do that, let us 

 get an idea not merely of the size of the sun, but his distance. 

 While the distance from here to the moon is a ten months' 

 journey by steam, the distance from here to the sun is more 



