[ 44-8 ] 
I beg leave to remind you of what has been lug- 
gefted, and inculcated, of a (I call it fuppofed) con- 
ftant influx of the waters through the Arait of Gi- 
braltar to the Mediterranean : with the difficulty oc- 
curring, to account how that immenfe f apply, (which 
fome ingenious worthy gentlemen have been at the 
trouble to calculate) befides what is poured in by many 
great rivers, can be expended. 
Vapour being deemed inlufficient far, recourfe is 
had to the notion of an under-current ; an idea to 
me, at firft glance, incompatible with nature, not- 
withffanding its being founded on an experiment 
made by a mafter of a fhip, in his paflage through 
the flrait, with a fair wind and good way through 
the water, by lowering a bucket certain number of 
fathoms deep; which remarkably abated the fhip’s 
way ; from whence I fuppofe the inference to be 
drawn. 
Now, that fuch a caufe fhould have fuch an effeCt, 
efpecially the reflflance of the water to be forced 
through at fo great a depth being f'o great, I take to 
be obvious. Befides, the fhip might have deviated 
in her fteerage from the ftream or llripe of water fhe 
was in, at the lowering of the bucket, into another 
counter-dream, which I fhall beg leave to offer to 
your confideration and correction by and by. 
Previous to any remark or reflection of mine on 
the matter, I entreat to be confidered abfolutely free 
from any motive whatever, but the hope of doing 
fomewhat more for the public utility, and having the 
honour of your approbation of the hints arifing from 
my obfervation. 
I made 
