• [ 458 ] 
The experiment had not, in the main point, the 
fuccefs we wifhed, for no material difference was 
obferved in the height or force of the furff upon the 
fl lore ; but thofe who were in the long-boat could 
obferve a tradt of fmoothed water, the whole length 
of the difcance in which the barge poured the oi!> 
and gradually fpreading in breadth towards the long- 
boat. I call it fmoothed, not that it was laid level ; 
but becaufe, though the fwell continued, its furface' 
was not roughened by the wrinkles, or fmaller waves, 
before-mentioned ; and none, or very few white- 
caps (or waves whofe tops turn over in foam) ap- 
peared in that whole fpace, though to windward 
and leeward of it there were plenty ; and a wherry, 
that came round the point under fail, in her way to 
Portfmouth, feemed to turn into that tra6t of choice, 
and to ufe it from end to end, as a piece of turn- 
pike- road. 
It may be of ufe to relate the circumftances even 
of an experiment that does not fucceed, lince they 
may give hints of amendment in future trials : it is 
therefore I have been thus particular. I fhall only 
add what I apprehend may have been the reafon of 
our dilappointment. 
I conceive, that the operation of oil on water is, 
firft, to prevent the railing of new waves by the 
wind ; and, fecondly, to prevent its pufhing thofe 
before raifed with fuch force, and confequently their 
continuance of the fame repeated height, as they 
would have done, if their furface were not oiled. 
But oil will not prevent waves being raifed by another 
power, by a hone, for inftance, falling into a ftill 
pool y for they then rife by the mechanical impulfe 
