32 THE PHYSICAL GEOGRAPHY OF THE SEA. 



miles greater when they enter the Atlantic than when they arrive 

 off the Banks of Newfoundland ; for in consequence of the differ- 

 ence of latitude between the parallels of these two places, their 

 rate of motion around the axis of the earth is reduced from nine 

 hundred and fifteen* to seven' hundred and fifty-eight miles the 

 hour. 



17. Therefore this immense volume of water would, if we sup- 

 pose it to pass from the Bahamas to the Grand Banks in an hour, 

 meet with an ojDposing force in the shape of resistance sufficient, 

 in the aggregate, to retard it two miles and a half the minute in its 

 eastwardly rate. If the actual resistance be calculated according 

 to received laws, it will be found equal to several atmospheres. 

 And by analogy, how inadequate must the pressure of the gentle 

 trade-winds be to such resistance, and to the effect assigned them ? 

 If, therefore, in the proposed inquiry, we search for a propelling 

 power nowhere but in the higher level of the Gulf, we must admit, 

 in the head of water there, the existence of a force capable of put- 

 ting in motion, and of driving over a plain at the rate of four 

 miles the hour, all the waters, as fast as they can be brought 

 down by three thousand (§6) such streams as the Mississippi 

 River — a power, at least, sufficient to overcome the resistance re- 

 quired to reduce from two miles and a half to a few feet per min- 

 ute the velocity of a stream that keeps in perpetual motion one 

 fourth of all the waters in the Atlantic Ocean. 



18. The facts, from observation on this interesting subject, af- 

 ford us at best but a mere glimmer of light, by no means sufficient 

 to make any mind clear as to a higher level of the Gulf, or as to 

 the sufficiency of any other of the causes generally assigned for 

 this wonderful stream. If it be necessary to resort to a higher 

 level in the Gulf to account for the velocity off Hatteras, I can not 

 perceive why we should not, with like reasoning, resort to a high- 

 er level off Hatteras also to account for the velocity off the Grand 

 Banks, and thus make the Gulf Stream, throughout its circuit, a 

 descending current, and, by the reductio ad ahsurdum, show that 



* Or, 915-26 to 75860. On the latter parallel the current has an east set of about 

 one and a half miles the hour, making the true velocity to the east, and on the axis 

 of the earth, about seven hundred and sixty miles an hour at the Grand Banks. 



