144 LIGHT SCIENCE FOR LEISURE HOURS. 



winds. Where the current flows most rapidly, namely, 

 in the Narrows of Bernini, it sets against the wind, and 

 for hundreds of miles after it enters the Atlantic, " it 

 runs," says JVIaury, " right in the ' wind's eye.' " It 

 must be remembered that a current of air directed 

 with considerable force against the surface of still 

 w r ater has not the power of generating a current which 

 can force its way far through the resisting fluid. If 

 this were so, we might understand how the current, 

 originating in sub-tropical regions, could force its way 

 onward after the moving force had ceased to act upon 

 it, and even carry the waters of the current right 

 against the wind, after leaving the Gulf of Mexico. 

 But experience, is w r holly opposed to this view. The 

 most energetic currents are quickly dispersed when 

 they reach a wide expanse of still water. For example, 

 the Niagara below the falls is an immense and rapid 

 river. Yet when it reaches Lake Ontario, " instead of 

 preserving its character as a distinct and well-defined 

 stream for several hundred miles, it spreads itself out, 

 and its w r aters are immediately lost in those of the 

 lake." Here, again, the question asked by Maury 

 bears pertinently on the subject we are considering. 

 " Why," he says, " should not the Gulf Stream do the 

 same ? It gradually enlarges itself, it is true ; but, 

 instead of mingling with the ocean by broad spread- 

 ing, as the immense rivers descending into the northern 

 lakes do, its waters, like a stream of oil in the ocean, 



