THE RING 181 



saw the edge of the ring as a thin rim of light, and, from 

 some spots seen on it, inferred that it rotated round the 

 planet in 10 hours, 32 minutes, 15 seconds. The planet 

 itself revolves in 10 hours, 14 minutes, 23 seconds. 



Highly interesting was the story thus told by the 

 planet ; but Herschel wrung from it other details. 

 He suspected that an eighth satellite existed, but it 

 was reserved for others to discover an eighth, and, it is 

 now said, a ninth, at great distances from the planet. 

 But the rings continued to be a puzzle, which baffled 

 solution. He observed lucid points, different from the 

 satellites, coming between the ring and his eye, and 

 moving along it in their orbits. If they were not 

 satellites, what were they ? He was not mistaken in 

 " the frequent appearance of protuberant and lucid 

 points on the arms of the ring of Saturn." They were 

 realities, not illusions, not an enchantment lent by the 

 vast distance at which he saw them. " Many of these 

 bright points," he writes, " were completely accounted 

 for by the calculated places of the satellites " ; but 

 there were many more which remained inexplicable. 

 He could not entertain the idea that these points 

 " would denote immense mountains of elevated sur- 

 face." He rather inclined to the belief that the ring 

 was in a state of rotation round the planet, and that 

 one at least of the shining spots might be a moon 

 bedded in or somehow connected with the ring, float- 

 ing, it might be, in a fluid like water, or running in 

 " a notch, groove or division of the ring to suffer the 

 satellite to pass along." He was perhaps not far from 

 the truth in these romantic imaginings. But the light 

 of the ring is generally brighter than that of the 

 planet, and he even imagined that the shining spots 



