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CANAL ACROSS THE ISTHMUS OF DARIEN. 
Canal across the Isthmus of Darien . 
The most colossal project of canalization ever suggested, 
whether we consider the physical difficulties of its execution, 
the magnitude and importance of the waters proposed to he 
united, or the distance which would be saved in navigation, is 
that of a channel between the Gulf of Mexico and the Pacific, 
across the Isthmus of Darien. I do not now speak of a lock 
canal, by way of the Lake of Nicaragua or any other route—• 
for such a work would not differ essentially from other canals, 
and would scarcely possess a geographical character—but of an 
open cut between the two seas. It has been by no means shown 
that the construction of such a channel is possible, and, if it 
were opened, it is highly probable that sand bars would accu¬ 
mulate at both entrances, so as to obstruct any powerful cur¬ 
rent through it. But if we suppose the work to be actually 
accomplished, there would be, in the first place, such a mixture 
of the animal and vegetable life of the two great oceans as I 
have stated to be likely to result from the opening of the Suez 
Canal between two much smaller basins. In the next place, 
if the channel were not obstructed by sand bars, it might sooner 
or later be greatly widened and deepened by the mechanical 
action of the current through it, and consequences, not inferior 
in magnitude to any physical revolution which has taken place 
since man appeared upon the earth, might result from it. 
What those consequences would be is in a great degree 
matter of pure conjecture, and there is much room for the ex¬ 
ercise of the imagination on the subject; but, as more than one 
geographer has suggested, there is one possible result which 
throws all other conceivable effects of such a work quite into the 
shade. I refer to changes in the course of the two great oceanic 
rivers, the Gulf Stream and the corresponding current on the 
Pacific side of the isthmus. The warm waters which the Gulf 
Stream transports to high latitudes and then spreads out, like 
an expanded hand, along the eastern shores of the Atlantic, 
give out, as they cool, heat enough to raise the mean tempera¬ 
ture of Western Europe several degrees. In fact, the Gulf 
