28 LIGHT SCIENCE FOR LEISURE HOURS. 



daily by our own atmosphere ; they probably pour in 

 countless millions upon the solar atmosphere ; and from 

 what we know of their numbers in our own neighbor- 

 hood, and of the probability of their being infinitely 

 more numerous in the neighborhood of the sun, we 

 have excellent reasons for believing that to them prin- 

 cipally is due the appearance of the zodiacal light and 

 the solar corona. 



(From Frascr^e Magazine, February, 1870.) 



THE EARTH A MAGNET. 



THERE is a very prevalent but erroneous opinion 

 that the magnetic needle points to the north. "We 

 remember well how we discovered in our boyhood that 

 the needle does not point to the north, for the discovery 

 was impressed upon us in a very unpleasant manner. 

 "We had purchased a pocket-compass, and were very 

 anxious not, indeed, to test the instrument, since we 

 placed implicit reliance upon its indications but to 

 make use of it as a guide across unknown regions. 

 Not many miles from where we lived lay Cobham 

 "Wood, no very extensive forest certainly, but large 

 enough to lose one's self in. Thither, accordingly, we 

 proceeded with three school-fellows. "When we had 

 lost ourselves, we gleefully called the compass into 

 action, and made from the wood in a direction which 



