THE ERRATIC PHENOMENA. 399 



Again, the action of this cause must have been such, and I insist 

 strongly upon this point, as a fundamental one, the momentum with 

 which it acted must have been such, that after being set in motion 

 in the north, with a power sufficient to carry the large boulders 

 which are found everywhere over this vast extent of land, it vanished 

 or was stopped after reaching the thirty-fifth degree of northern 

 latitude. 



Now it is my deliberate opinion that natural philosophy and math- 

 ematics may settle the question, whether a body of water of sufficient 

 extent to produce such phenomena can be set in motion with sufficient 

 velocity to move all these boulders, and nevertheless stop before hav- 

 ing swept over the whole surface of the globe. Hydrographers are 

 familiar with the action of currents, with their speed, and with the 

 power with which they can act. They know also how they are distrib- 

 uted over our globe. And, if we institute a comparison, it will be seen 

 that there is nowhere a current running from the poles towards the 

 lower latitudes, either in the northern or southern hemisphere, cover- 

 ing a space equal to one-tenth of the currents which should have 

 existed to carry the erratics into their present position. The widest 

 current is west of the Pacific, which runs parallel to the equator, 

 across the whole extent of that sea from east to west, and the great- 

 est width of which is scarcely fifty degrees. This current, as a 

 matter of course, establishes a regular rotation between the waters 

 flowing from the polar regions towards lower latitudes. 



The Gulf Stream on the contrary runs from west to east, and dies 

 out towards Europe and Africa, and is compensated by the currents 

 from Baffin's Bay and Spitzbergen emptying into the Atlantic, while 

 the current of the Pacific, moving towards Asia and carrying floods 

 of water in that direction, is maintained chiefly by antarctic currents, 

 and those which follow the western shore of America from Behring's 

 Straits. Wherever they are limited by continents, we see that 

 the waters of these currents, even when they extend over hundreds of 

 degrees of latitude, as the Gulf Stream does in its whole course, are 

 deflected where they cannot follow a straight course. 



Now without appealing with more detail to the mechanical con- 

 ditions involved in this inquiry, I ask every unprejudiced mind 

 acquainted with the distribution of the northern boulders, whether 



