CURRENTS AND WHALING. 457 



tribution of the temperature at the surface of the ocean is affected by- 

 causes very different from those which are usually considered to be 

 the only ones in action. 



In order to obtain precision of language, I have chosen to dis- 

 tinguish between streams and currents, employing the former term to 

 express the movements of water by which the circulation of the great 

 mass of the ocean is maintained, and confining the latter to those less 

 extensive in their influence, or local in their effects ; and the direction 

 from whence the great streams are derived as polar and equatorial. 



I shall now proceed to speak of the streams which we met with on 

 our voyage, citing, whenever it is necessary, such facts derived either 

 from general experience, or the authority of individual observers, as 

 may be useful to extend the inferences, or verify our own observa- 

 tions. 



Immediately after our departure from the capes of Virginia, we felt 

 the influence of a stream setting to the southward, and parallel to the 

 coast. The existence of this was apparent from our first observation 

 of latitude. It may, however, often escape notice, as the navigator is 

 apt to ascribe the effect of this stream rather to an error in taking his 

 departure, than to set of current. In order that the fact may be 

 clearly perceived, it is necessary that the distance of the vessel from 

 the lighthouse, or other object on shore with which the dead reckon- 

 ing begins, should be determined by precise observations, instead of 

 being merely estimated, as is the usual mode. Notwithstanding the 

 inaccuracy growing out of this cause, it has been long known to 

 seamen that a counter-current is setting' close to the inner edge of the 

 Gulf Stream, and has been distinguished by them as its eddy. That 

 it cannot be of the nature of an eddy of that heated body of water, is 

 evident from the great difference of temperature, which falls suddenly 

 fifteen or twenty degrees, in passing from the Gulf Stream into that 

 which flows in an opposite direction. The latter is also five to ten, 

 and even fifteen degrees colder, according to the season, than the 

 waters of our bays or rivers. 



The inner stream flowing to the southwest is now well known to 

 exist along our whole eastern coast and that of Nova Scotia, and the 

 masters of our packet-ships have by experience discovered the value 

 of which it may be to them in their homeward passage. This they 

 do by keeping to the north of the forty-second parallel until off Cape 

 Sable. 



