prevails to the westward of the Stilly Islands. 187 
known to run nine hours to the northward ; but the ebb, in 
the opposite direction, only three hours. This particular had 
not come to my knowledge, when the Paper of 1793 was 
written. 
VI. But the most satisfactory proof, not only of the exist- 
ence of a northerly current, athwart the mouths of the British 
and Irish channels, but also of its velocity (at least during cer- 
tain intervals), is a statement in a book published in 1733, 
entitled Joshua Kelly’s Treatise of Navigation,* (in two 
volumes octavo). This case is the more satisfactory, as it 
happened in a dead calm of forty-eight hours continuance : so 
that all uncertainty, regarding the accuracy of a sea reckon- 
ing, allowances for leeway, drift ; &c. is precluded ; since 
the changes of position that took place, could only have been 
effected by the motion of the sea, either in the nature of a 
current, or of a tide: and this latter must be placed out of the 
question, since the interval of time, included no less a space 
than that in which four fluxes, and as many refluxes have their 
periods : so that they may well be supposed to balance each 
other. 
“ It has been observed (says Mr. Kelly )-f by an experi- 
“ enced commander, who used the West India Voyages for 
“ many years, from England, (in his return from one of 
“ these) that in about the latitude of 48° 3©', open with our 
“ British channel, having a good observation (of latitude) at 
“ the same time, it proving calm and smooth water, insomuch 
“ that he handed his sails, and so lay forty-eight hours. The 
* This was originally pointed out to me by Mr. John Purdy, the very able 
fiydrographer, employed by Messrs. Lawrie and Whittle, Fleet-street. 
+ Volume the first, page 434. 
B b 2 
