42 PHYSICAL GEOGBAPHT OF THE SEA, AND ITS METEOROLOGY. 



stones, and gravel brought down upon these bergs are here 

 depos-ited. Captain Scoresby, far away in the north, counted at 

 one time five hundred icebergs setting out from the same vicinity 

 upon this cold current for the south. Many of them, loaded 

 with earth, have been seen aground on the Banks. This process 

 of transferring deposits from the north for these shoals, and of 

 snowing down upon them the infusoria and the corpses of 

 " living creatures " that are brought forth so abundantly in the 

 warm waters of the Gulf Stream, and delivered in myriads for 

 burial Avhere the conflict between it and the great Polar current 

 (§ 89) takes place, is everlastingly going on. These agencies, 

 with time, seem altogether adequate to the formation of extensive 

 bars or banks. 



117. Beep loater near. — The deep-sea soundings that have been 

 made by vessels of the English and American navies (Plate XI.) 

 tend to confirm this view as to the formation of these Banks. 

 The greatest contrast in the bottom of the Atlantic is just to the 

 south of these Banks. Kowhere in the open sea has the water 

 been found to deepen so suddenly as here. Coming from the 

 north, the bottom of the sea is shelving; but suddenly, after 

 passing these Banks, it dips down by a precipitous descent to 

 unknown depths — thus indicating that the debris which forms 

 the Grand Banks comes from the north. 



118. TJie' Gulf Stream describes in its course tlie path of a tra- 

 jectory. — Prom the Straits of Bemini the course of the Gulf 

 Stream (Plate VI.) describes (as far as it can be traced over 

 toward the British Islands which are in the midst of its waters) 

 the arc of a great circle nearly. Such a course as the Gulf 

 Stream takes is very nearly the course that a cannon-ball, could 

 it be shot from these straits to those islands, would follow. 



119. Its path from Bemini to Ireland. — If it vfere possible to see 

 Ireland from Bemini, and to get a cannon that would reach that 

 far, the person standing on Bemini and taking aim, intending to 

 shoot at Ireland as a target, would, if the earth were at rest, 

 sight direct, and make no allowance for difference of motion 

 between marksman and target. Its path would lie in the plane 

 of a great circle. But there is diurnal rotation ; the earth does 

 revolve on its axis ; and since Bemini is nearer to the equator 

 than Ireland is, the gun would be moving in diumal rotation 

 (§91) faster than the target, and therefore the marksman, taking 

 aim point blank at his target, would miss. He w^ould find, on 



