170 On the Gulf Stream and Currents of the Sea. 



throughout. On such a globe, the equiUbrium remaining undis- 

 turbed, there would be neither wind nor current ; and the poet's 

 picture would apply to every sea : 



" Still as a slave before his lord, 

 The ocean hath no blast — 

 His great bright eye most silently 

 Up to the moon is cast." 



Let us now suppose the globe to receive diurnal motion, and that 

 all the water within the tropics, to the depth of one hundred 

 fathoms, suddenly becomes oil, the aqueous equilibrium of the 

 planet is thereby disturbed, and a general system of currents 

 and counter-currents is immediately commenced — the oil, in an 

 unbroken sheet on the surface, running towards the poles, and 

 the water, in an under-current, towards the equator. 



Thus, without wind, we should have a perpetual and uniform 

 system of tropical and polar currents. 



In consequence of diurnal rotation of the planet on its axis, each 

 particle of oil, were resistance small, would approach the poles on 

 a spiral turning to the east, with a relative velocity greater and 

 greater, until finally it would reach the pole, and whirl about it at 

 nearly the rate of one thousand miles the hour. Becoming water, 

 and losing its velocity, it would approach the tropics by a similar 

 but inverted spiral turning towards the west. For this reason, all 

 currents, from the equator to the poles, should have an eastward 

 tendency, and all from the poles towards the equator, a westward. 



Let us suppose, further, that the solid nucleus of this hypothet- 

 ical globe assumes the exact shape and form of the bottom of our 

 seas, and that in all respects, as to figure and size, it represents the 

 shoals and islands of the sea, as well as the coast lines and conti- 

 nents of the earth. The uniform system of currents just describ- 

 ed would now be interrupted by obstructions and local causes of 

 various kinds, such as unequal depth of water, contour of shore 

 lines, &c., and we should have, at certain places, currents greater 

 in volume and velocity than at others. But still there would be 

 a system of currents, and of counter-currents, to and from either 

 pole and the equator. Now, do not the cold waters of the north, 

 and the warm waters of the Gulf, made specificalljr hghter by 

 tropical heat, which we see actually preserving such a system of 

 counter-currents, hold, at least in some degree, the relation of the 

 supposed oil and water. 



