300 NINETEENTH CENTURY. FT. in. 



suppose that these hundred meteor-systems which we come 

 across are the only ones existing. On the contrary, we 

 have every reason to think that they are only a few out of 

 thousands of meteor-systems which we never meet, and 

 which must grow more numerous the nearer they approach 

 the sun. 



And so we arrive at the wonderful thought that the 

 whole of our solar system is swarming with meteors rushing 

 along with immense speed ! What their use is we do not 

 know. Some astronomers imagine that the heat of the sun is 

 kept up by these meteoric stones falling in countless myriads 

 on his face, but this is disputed by others ; and for the pre- 

 sent it is enough if we can picture to ourselves these rings 

 of meteors Whirling round and round in space, and flash- 

 ing into light as they rush through our atmosphere whenever 

 we happen to cross their path. 



I have chosen out these new facts about meteors be- 

 cause, of all modern discoveries, they give the best idea of 

 the wide fields of knowledge which are opening out before 

 us. Within the last fifty years a number of most interesting 

 observations have been made about the nature of tfie S un 

 itself; but they would require long explanations, and being 

 all the work of living men they scarcely belong to our 

 history. 



In the chapter on Spectrum Analysis we shall learn some- 

 thing of the atmosphere of the sun and stars, and in the 

 chapter on Magnetism something of the spots on the sun 

 and their effects on our earth. But for the history of the 

 discovery of the photosphere, corona, red prominences, and 

 other wonderful appearances upon the face of the sun, you 

 must read special works on the subject. 



