168 Oil the Gulf Stream and Currents of the Sea. 



been altered since that time. This indication of a circular mo- 

 tion by the Gulf Stream is corroborated by the bottle chart and 

 other sources of information. If therefore this be so, why give 

 the endless current a higher level in one part of its course than 

 another ? 



Nay, more ; at the very season of the year when the Gulf 

 Stream is rushing in greatest volume through the Straits of Flo- 

 rida and hastening to the north with the greatest rapidity, there 

 is a cold stream from Baffin's Bay, Labrador, and the coasts of 

 the north, running to the south with equal velocity. The two 

 meet off the Grand Banks, where the latter is divided, one part 

 of it runs under the Gulf Stream, as is shown by the icebergs 

 which are carried in a direction tending across its course. The 

 probability is that this "fork" continues on towards the south, 

 and runs into the Caribbean Sea; for the temperature of the wa- 

 ter at a little depth there has been found far below the mean 

 temperature of the earth, and quite as cold as at a corresponding 

 depth off the arctic shores of Spitzbergen. The other fork runs 

 between us and the Gulf Stream as already described. As fer 

 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* 



The power necessary to overcome the resistance opposed to 

 such a body of water as that of the Gulf Stream running several 

 thousand miles, without any renewal of impulse from the forces 

 of gravitation or any other known cause, is truly astonishing. 

 It so happens that we have an argument for determining this re- 

 sistance towards the east with a degree of accuracy. Owing to 

 the diurnal rotation, the waters of this stream are carried round 

 with the earth on its axis, towards the east, with an hourly velo- 

 city one hundred and fifty sevenf miles greater when they enter 

 the Atlantic, than W'hen they arrive off the banks of Newfound- 

 land. In consequence of the difference of latitude between the 



* More water cannot run from the equator or the pole than to it. If we make 

 the trade winds cause the former, some other wind must produce the latter. But 

 there are no trade winds about the poles, and currents from these regions are for 

 the most part (as the Labrador current after it meets the Gulf Stream) beloic the 

 surface, and therefore beyond the influence of any wind whatever. Hence it 

 would seem that trade winds have but little to do with the general system of 

 aqueous circulation in the ocean. 



t In this calculation, the earth is treated as a perfect sphere, with a diameter of 

 7925-56 miles. 



