Il8 LIGHT SCIENCE FOR LEISURE HOURS. 



meantime made the circuit of the Gulf as it issues 

 from the Bernini Straits. All the maps in which the 

 Atlantic currents are depicted present precisely such 

 an outside current as I have here spoken of, and 

 most of them assign to it a width exceeding that of 

 the Bernini current. Indeed, were it not for the doubts 

 which the recent discussions have thrown upon all the 

 currents charted by seamen, I should have been con- 

 tent to point to this outside current as shown in the 

 maps. As it is, I have thought is necessary to show 

 that such a current must necessarily have an existence, 

 since we cannot lose sight of the influence of the West 

 Indian Isles in partially damming up the passage along 

 which the equatorial current would otherwise find its 

 way into the Gulf of Mexico. Whatever portion of 

 the great current is thus diverted must find a passage 

 elsewhere, and no passage exists for it save along the 

 outside of the West Indian Isles. 



The possibility that the wide current which has 

 been assumed to traverse the mid- Atlantic may be as- 

 sociated with the waters which flow from the Gulf of 

 Mexico, either through the Narrows or round the out- 

 side of the barrier formed by the West Indies, has 

 thus been satisfactorily established. But we now have 

 to consider difficulties which have been supposed to 

 encounter our current on its passage from the Gulf to 

 the mid-Atlantic. 



Northwards, along the shores of the United States, 

 the current has been traced by the singular blueness 

 of its waters until it has reached the neighbourhood 



