326 PHILOSOPHICAL TRANSACTIONS. [aNNO 17Q3. 



mander, jjrudent in his measures, but unsuspicious of a current, would choose to 

 sail in. 



It seems to be generally allowed, that there is always a current, setting round 

 the Capes of Finisterre, and Ortegal, into the Bay of Biscay. This I have the 

 authority of Capt. Mendoza Rios, a f. r. s., and an officer in the royal navy of 

 Spain, for asserting. Besides, such an intimation was among the earliest notices 

 that I received, concerning matters of navigation, when on board of a ship that 

 sailed close along the north coast of Spain, in 1757. The current then is ad- 

 mitted to set to the eastward, along the coast of Spain; and continues its course, 

 as I am assured, along the coast of France, to the north, and north-west: and 

 indeed, any body of water, once set in motion, along a coast, cannot suddenly 

 stop; nor does it probably lose that motion, till by degrees it mixes with the 

 ocean; after being projected into it, either from the side of some promontory, 

 that extends very far beyond the general direction of the coast; or after being 

 conducted into it, through a strait. 



The original cause of this current, I apprehend to be the prevalence of westerly 

 winds in the Atlantic; which, impelling the waters along the north coast of 

 Spain, occasions a current in the first instance. The stronger the wind, the 

 more water will be driven into the Bay of Biscay, in a given time; and the 

 longer the continuance of the wind, the farther will the vein of current extend. 

 It seems to be clearly proved, that currents of water, after running along a coast 

 that suddenly changes its direction, (as happens on the French coast at the pro- 

 montory south of Brest) do not change their course with that of the shore, but 

 preserve, for a considerable time, the direction they received from the coast they 

 last ran by. In some instances, after being projected into the sea, they never 

 again approach the shore; but preserve, to a very great distance, nearly the direc- 

 tion in which they were projected; as well as a considerable degree of their ori- 

 ginal velocity, and temperature. The gulf stream, of Florida, is a wonderful 

 instance of this kind; which, originating in a body of pent-up waters, in the 

 Gulf of Mexico, is discharged with such velocity, through the Straits of Bahama, 

 that its motion is traceable through the x\t]antic, to the bank of Newfoundland; 

 and may possibly extend much farther. This being therefore the case, we can 

 have no difficulty in conceiving, that the current of the Bay of Biscay continues 

 its course, which may be about n.w. by w., from the coast of France, to the 

 westward of Scilly and Ireland. 



At ordinary times, its strength may not be great enough to preserve its line of 

 direction, across the mouth of the British Channel ; or, if it does preserve its 

 direction, it may not have velocity enough to throw a ship so far out of her 

 course, as to put her in danger. But, that a current prevails generally, there 

 can be little doubt ; and its degree of strength will be regulated by the state of 



