THE GULF STEEAM. 31 



circulation in the ocean. The other "fork" runs between our 

 shores and the Gulf Stream to the south, as already described. 

 As tar as it has been traced, it warrants the belief that it, too, 

 runs up to seek the so-called higher level of the Mexican Gulf. 



91. Effects of diurnal rotation upon the Gulf Stream. — The power 

 necessary to overcome the resistance opposed to such a body of 

 water as that of the Gulf Stream, running several thousand miles 

 v,dthout any renewal of impulse from the forces of gravitation or 

 any other known cause, is truly surprising. It so happens that 

 we have an argument for determining, with considerable ac- 

 curacy, the resistance which the waters of this stream meet with 

 in their motion towards the east. Owing to the diurnal rotation, 

 they are carried around with the earth on its axis toivards the 

 east, with an hourly velocity of one hundred and fifty-seven* 

 miles greater when they enter the Atlantic than when they 

 arrive off the Banks of Newfoundland ; for in consequence of the 

 difference 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 fifteenj to seven hundred and fifty-eight miles 

 the hour. Hence this immense volume of water would, if we 

 suppose it to pass from the Bahamas to the Grand Banks in an 

 hour, meet with an opposing 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 eftect assigned them ! 



92. TJie Gulf Stream cannot he accounted for hy a higher level. — 

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

 power nowhere but in the higher level of the Gulf, or in the 

 " billiard-ball " rebound from its shores, we must admit, in the 

 head of water there, the existence of a force capable of putting in 

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

 hour, all the w^aters, as fast as they can be brought down by three 



* lu tliis calculation the eaiiii is treated as a perfect sphere, with a diameter 

 of 7923.56 miles. 



t Or, 915.2G to 758.60. On the latter parallel the ciuTcnt has an east set ot 

 about one and a half mile 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. 



