134 LIGHT SCIENCE FOR LEISURE HOURS. 



an outside current as we liave 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, we should have 

 been content to point to this outside current as shown 

 in the maps. As it is, we have thought it 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 pas- 

 sage 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 

 associated with the waters which flow from the Gulf 

 of Mexico, either through the Narrows or round the 

 outside 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. 



Northward, along the shores of the United States, 

 the current has been traced by the singular blueness 

 of its waters until it has reached the neighborhood of 



