38 THE PHYSICAL GEOGRAPHY OF THE SEA. 



114. It is in consequence of this diurnal rotation that drifl- 

 Drift-wood on the ^ood comiug down the Mississippi is so very apt 

 Mississippi. ^Q ]3Q ^^g^ upon the west or right bank. This is the 

 reverse of what obtains upon the Gulf Stream, for it flows to the 

 north ; it therefore sloughs off (§ 111) to the east. 



115. The effect of diurnal rotation upon the winds and upon 

 Effect of diurnal ro- ^^^ currcuts of the sca is admitted by all — the trade- 

 tationupon. wluds dcrivc their easting from it — it must, there- 

 fore, extend to all the matter which these currents bear with them, 

 to the largest iceberg as well as to the smallest spire of grass that 

 floats upon the waters, or the minutest organism that the most 

 powerful microscope can detect among the impalpable particles 

 of sea-dust. This effect of diurnal rotation upon drift will be fre- 

 quently alluded to in the pages of this work. 



116. In its course to the north, the Gulf Stream gradually trends 

 Formation of the ^lore and morc to the eastward, until it arrives off 

 Grand Banks. j^^ Bauks of Kcwfouudlaud, whcrc its course be- 

 comes nearly due east. These banks, it has been thought, deflect 

 it from its proper course, and cause it to take this turn. Exam- 

 ination will prove, I think, that they are an effect, certainly not 

 the cause. It is here that the frigid current already spoken of 

 (§ 85), and its icebergs from the north, are met and melted by the 

 warm waters of the Gulf. Of course the loads of earth, stones, 

 and gravel brought down upon these bergs are here deposited. 

 Captain Scoresby, far away in the north, counted at one time five 

 hundred icebergs Getting 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 trans- 

 ferring deposits from the north for these shoals, and of snowing 

 down upon them the infusoria and the corpses of "living crea- 

 tures" that are brought forth so abundantly in the warm waters of 

 the Gulf Stream, and delivered in myriads for burial where the 

 conflict between it and the great Polar current (§ 89) takes place, 

 is everlastingly going on. These agencies, with time, seem alto- 

 gether adequate to the formation of extensive bars or banks. 



117. The deep-sea soundings that have been made by vessels of 

 Deep water near, thc navy (Plate XI.) tend to confirm this view as to 



the formation of these Banks. The greatest contrast in the bot- 

 tom of the Atlantic is just to the south of these Banks. Nowhere 



