5& C.C. NATURAL HISTORY SOCIETY. 



wards clouds condensed on its surface and so the sea was formed. 



In the Moon the same course of events occurred, but owing to 

 the smallness in size of the Moon the internal pull on the solid crust 

 was soon insufficient to break it up and then the still cooling interior 

 shrank away from the solid crust, and when afterwards the latter 

 developed weak places the waters rushed in, came into contact with 

 the heated interior and the resulting ex])losions, whose magnitude we 

 can scarcely conceive, rent the crust and left it permanently altered, 

 su that at the present day, when we look at the Moon, its surface 

 looks just like one mass of ancient volcanoes. 



The Planets are to be distinguished from other stars by the fact 

 that they appear to wander about in the heavens, new ones are being 

 continually being discovered, the last one being found in Germany 

 last August. 



Saturn is one of the most beautiful of the planets on account of 

 its rings. For a long time the composition of these rings was not proved. 

 If they were solid rings tney would have to be far stronger than any- 

 thing we know of on Elarth, or they would get ruptured as they swung 

 round the planet. And we now know that they are really composed of 

 a large number of small bodies and not of one solid mass. If they were 

 a solid the outer rim would have to be travelling at a faster rate than 

 the inner one for the ring to keep together. But if they were 

 a number of little bodies, the inner ones would have to be rotating 

 faster than the outer ones, for they are nearer to the planet and there- 

 fore the attraction towards the planet is greater, and so in order to 

 prevent themselves being drawn in they must be swinging round at a 

 very rapid pace and faster than the outer run. 



Now by means of an instrument, called the Spectrometer, we can 

 tell whether a body is approaching or departing from us and also its 

 speed, by observing the light it gives out during its motion. And the 

 Spectrometer informs us that the inner parts of Saturn's rings are 

 going round faster than the outer parts and consequently the rings 

 cannot be solid but must be formed by a number of little bodies 

 all sweeping round their planet. 



