THE PLANETS, ARE THEY INHABITED \ 



coincident with, the plane of the Saturnian equator. The conse- 

 quence of this arrangement is, that they are always visible by 

 the inhabitants of both hemispheres when they are not eclipsed 

 by the shadow of the planet. 



The motion of the nearest moon is so rapid as to be per- 

 ceivable by the Saturnians like that of the hour-hand of a 

 colossal timepiece. It describes 360 in 22J hours, being at the 

 rate of 16 per hour, or 16' per minute, so that in two minutes it 

 moves over a space equal to the apparent diameter of the moon. 



The eighth, or most remote satellite, is in many respects ex- 

 ceptional, and different from all the others. Unlike these, it 

 moves in an orbit inclined at a considerable angle to the plane of 

 the equator. 



Owjing to the great distance of Saturn, the dimensions of the 

 satellites have not been ascertained. The sixth in order, proceed- 

 ing outwards, called Titan, is, however, known to be the largest, 

 and it appears certain that its volume is little less than that of 

 the planet Mars. The three satellites immediately within this, 

 Ehea, Dione, and Tethys, are smaller bodies, and can only be 

 seen with telescopes of. great power. The two nearest, Enceladus, 

 and Mimas, require instruments of the very highest power and 

 perfection, and atmospheric conditions of the most favourable 

 nature, to be observable at all. 



The real magnitudes of the satellites, the sixth excepted, being 

 unascertained, nothing can be inferred with any certainty 

 respecting their apparent magnitudes as seen from the surface of 

 Saturn, except what may be reasonably conjectured upon analogies 

 to other like bodies of the system. The satellites of Jupiter 

 being all greater than the moon, while one of them exceeds 

 Mercury in magnitude, and another is but little inferior in 

 volume to that planet, it may be assumed with great probability 

 of truth that the satellites of Saturn are at least severally 

 greater in their actual dimensions than our moon. 



48 



