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Sir John pringle and Dr. franklin. According 
to his reprefentation, the water, which had been in 
great agitation before, was inftantly calmed, upon 
pouring in only a very fmall quantity of oil, and that 
to fo great a diftance round the boat as feems a little 
incredible. I have lince had the fame accounts from 
others, but I fufpedt all of a little exaggeration. 
pliny mentions this property of oil as known parti- 
cularly to the divers, who made ufe of it in his days, 
in order to have a more fteady light at the bottom(rf). 
The Tailors, I have been told, have obferved fome- 
thing of the fame kind in our days, that the water 
is always remarkably fmoother in the wake of a £hip 
that hath been newly tallowed, than it is in one that 
is foul. — Mr. pennant alfo mentions an obferva- 
tion of the like nature made by the feal catchers in 
Scotland. Brit. Zool. Vol. iv. Article seal. When 
thefe animals are devouring a very oily fifh, which 
they always do under water, the waves above are 
obferved to be remarkably fmooth, and by this mark 
the filhermen know where to look for them. — Old 
pliny does not ufually meet with all the credit I am 
inclined to think he deferves. I fhall be glad to have an 
authentic account of the Kefwick experiment, and if 
Note by Dr. brownrigg. 
(a) Sir gilfred lawson, who ferved long in the army at 
Gibraltar, allures me that the fifhermen in that place are ac- 
cuftomed to pour a little oil on the - fea, in order to ftill its motion, 
that they may be enabled to fee the oyfters lying at its bottom ; 
which are there very large, and which they take up with a pro- 
per inftrument. This Sir gilfred had often feen there per- 
formed, and faid the fame was pra&ifed on other parts of the 
Spanifh coaft. 
it 
