J50 LIGHT SCIENCE FOR LEISURE HOURS. 



the overflow conceived by Maury should result in an 

 easterly instead of a westerly current. Recently the 

 theory was put forward that the continual process of 

 evaporation going on in the equatorial regions leads to 

 an indraught of cold water in bottom-currents from the 

 polar seas. Such currents coming towards the^equator, 

 that is,, travelling from latitudes where) the earth's east- 

 wardly motion is less to latitudes in which that motion 

 is greater, would lag behind, that is, would have a 

 westwardly motion. It seems now placed beyond a 

 doubt that this is the true explanation of the equatorial 

 ocean-currents. 



Such are a few, and but a few, among the many 

 interesting results which have followed from the recent 

 researches of Dr. Carpenter and Professor Thomson 

 into the hitherto little-known depths of the great sea. 

 (From the Spectator, December 4, 1869.) 



THE TUNNEL THROUGH MONT CENIS. 



MEN flash their messages across mighty continents and 

 beneath the bosom of the wide Atlantic ; they weigh 

 the distant planets, and analyse the sun and the stars ; 

 they span Niagara with a railway bridge, and pierce the 

 Alps with a railway tunnel : yet the poet of the age in 

 which all these things are done or doing sings, ' We 

 men are a puny race.' And certainly, the great works 

 which belong to man as a race can no more be held to 

 evidence the importance of the individual man than the 

 vast coral reefs and atolls of the Pacific can be held to 



