Mr. Renneli/s Observations on a Current , &c. 183 
referred to accident ; and therefore no attempt seems to have 
been made, to investigate the cause of them. 
I am however of opinion, that they may be imputed to a 
specific cause ; namely, a current : and I shall therefore en- 
deavour to investigate both that, and its effects ; that seamen 
may be apprized of the times, when they are particularly to 
expect it, in any considerable degree of strength ; for then 
only, it is likely to occasion mischief ; the current that pre- 
vails at ordinary times, being, probably, too weak to produce 
an error in the reckoning, equal to the difference of parallel, 
between the south part of Scilly, and the track that a com- 
mander, prudent in his measures, but unsuspicious of a cur- 
rent, would chuse 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 Captain 
Mendoza Rios, a Fellow of the Royal Society, and an officer 
in the royal navy of Spain, for asserting. Besides, such an inti- 
mation was amongst the earliest notices that I received, con- 
cerning matters of navigation, when on board of a ship that 
sailed close along the north coast of Spain, in 1757. The cur- 
rent then, is admitted 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, until 
• 
* It may be remarked, by the way, that the true latitude of the present light- 
house on St. Agnes’s Island, is 49 0 , 54'; and that of the most southerly part of the 
whole group of islands and rocks, is 49 0 , 52'. This is according to an advertisement 
giyen out by the Trinity House, in 1792. 
2 B 2 
