t +53 ] 
A fmall power continually operating will produce 
a great afiion. A finger applied to a weighty fuf- 
pended bell, can at firft move it but little ; if re- 
peatedly applied, though with no greater flrength, 
the motion increafes till the bell fwings to its utmoft 
height, and with a force that cannot be refilled by the 
whole flrength of the arm and body. Thus the 
fmall firfl-raifed waves, being continually a<?:ed up- 
on by the wind, are, though the wind does not in- 
crease in flrength, continually increafed in magni- 
tude, rifing higher and extending their bafes, fo as 
to include a vafl mafs of water in each wave, which 
in its motion a&s with great violence. 
But if there be a mutual repulfion between the 
particles of oil, and no attradlion between oil and 
water, oil dropt on water will not be held together 
by adhefion to the fpot whereon it falls ; it will not 
be imbibed by the water ; it will be at liberty to ex- 
pand itielf ; and it will fpread on a furface that, be- 
lides being fmooth to the mofl perfect degree of 
polilh, prevents, perhaps by repelling the oil, all im- 
mediate contact, keeping it at a minute diflance from 
itfelf 3 and the expanfion will continue, till the mu- 
tual repulfion between the particles of the oil is 
weakened and reduced to nothing by their diflance. 
Now I imagine that the wind blowing over water 
thus covered with a film of oil, cannot eafily catch 
upon it, fo as to raile the firft wrinkles, but Aides 
over it, and leaves it fmooth as it finds it. It moves 
a Jittle the oil indeed, which, being between it and 
the water, ferves it to Aide with, and prevents fridtion, 
as oil does between thofe parts of a machine, that 
would othenvife rub hard together. Hence the 
oil 
