Curiosities of Science. 81 



to make one of the bulk of Jupiter. A railway-engine travel- 

 ling at the rate of thirty- three miles an hour would travel 

 round the earth in a month, but would require more than 

 eleven months to perform a journey round Jupiter. 



WAS SATURN'S RING KNOWN TO THE ANCIENTS ? 



In Maurice's Indian Antiquities is an engraving of Sani, 

 the Saturn of the Hindoos, taken from an image in a very an- 

 cient pagoda, which represents the deity encompassed by a ring 

 formed of two serpents. Hence it is inferred that the ancients 

 were acquainted with the existence of the ring of Saturn. 



Arago mentions the remarkable fact of the ring and fourth 

 satellite of Saturn having been seen by Sir W. Herschel with 

 his smaller telescope by the naked eye, without any eye- piece. 



The first or innermost of Saturn's satellites is nearer to the 

 central body than any other of the secondary planets. Its dis- 

 tance from the centre of Saturn is 80,088 miles ; from the sur- 

 face of the planet 47,480 miles ; and from the outmost edge of 

 the ring only 4916 miles. The traveller may form to himself 

 an estimate of the smallness of this amount by remembering 

 the statement of the well-known navigator, Captain Beechey, 

 that he had in three years passed over 72,800 miles. 



According to very recent observations, Saturn's ring is di- 

 vided into three separate rings, which, from the calculations 

 of Mr. Bond, an American astronomer, must be fluid. He is 

 of opinion that the number of rings is continually changing, 

 and that their maximum number, in the normal condition of 

 the mass, does not exceed twenty. Mr. Bond likewise maintains 

 that the power which sustains the centre of gravity of the ring 

 is not in the planet itself, but in its satellites ; and the satellites, 

 though constantly disturbing the ring, actually sustain it in the 

 very act of perturbation. M. Otto Struve and Mr. Bond have 

 lately studied with the great Munich telescope, at the observa- 

 tory of Pulkowa, the third ring of Saturn, which Mr. Lassell and 

 Mr. Bond discovered to \& fluid. They saw distinctly the dark 

 interval between this fluid ring and the two old ones, and even 

 measured its dimensions ; and they perceived at its inner mar- 

 gin an edge feebly illuminated, which they thought might bo 

 the commencement of a fourth ring. These astronomers are of 

 opinion, that the fluid ring is not of very recent formation, and 

 that it is not subject to rapid change; and they have come to 

 the extraordinary conclusion, that the inner border of the ring 

 has, since the time of Huygens, been gradually approaching to 

 the body of Saturn, and that we may expect, sooner or later, 

 perhaps in sortie dozen of years, to see the rings united with the 

 body of the planet. But this theory is by other observers pro- 

 nounced untenable. 



