212 LIGHT SCIENCE FOR LEISURE HOURS. 



stream which is the necessary consequence of the con- 

 tinual flow of the great western equatorial current 

 against the barrier formed by the American continent. 

 It would require much more space than I have at my 

 disposal to deal at length with the subject of my paper. 

 I therefore conclude by referring my readers to Maury's 

 interesting work on the 'Physical Geography of the 

 Sea,' with the remark that his views seem to me only 

 to require the mainspring or starting force towards the 

 west which I have ventured to suggest, to supply a 

 complete, efficient, and natural explanation of the whole 

 series of phenomena presented by the great ocean- 

 currents. 



The Student for July 1868. 



OCEANIC CIRCULATION. 



THEKE are some questions, seemingly innocent enough, 

 which yet appear fated to rouse to unusual warmth all 

 who take part in their discussion. One cannot, for 

 instance, find anything obviously tending to warmth of 

 temper in the telescopic study of a planet ; yet the 

 elder Cassini was moved to passionate invective by cer- 

 tain observations of Mars not perfectly according with 

 his own ; and Sir W. Herschel, usually so philosophic, 

 was roused by Schroter's recognition of mountains in 

 Venus to deliver himself of a criticism justly described 



