[ 459 ] 
of the ftone, which the greafmefs on the fur- 
rounding water cannot lefien or prevent, as it can 
prevent the winds catching the furface and raifing it 
into waves. Now waves once raifed, whether by 
the wind or any other power, have the fame me- 
chanical operation, by which they continue to rife 
and fall, as a pendulum will continue to fwing, a 
long time after the force ceafes to aft by which the 
motion was firft produced : that motion will, how- 
ever, ceafe in time ; but time is necefiary. There- 
fore, though oil fpread on an agitated fea, may 
weaken the pufh of the wind on thofe waves whole 
furfaces are covered by it, and fo, by receiving lefs 
frelh impulfe, they may gradually fubfide; yet a 
confiderable time, or a diftance through which they 
will take time to move, may be necelfary to make 
the effeft fenfible on any fhore in a diminution of 
the furff; for we know, that when wind ceafes 
fuddenly, the waves it has raifed do not as fuddenly 
fubfide, but fettle gradually, and are not quite down 
till long after the wind has ceafed. So though we 
fhould, by oiling them, take off the effect of wind 
on waves already raifed, it is not to be expected that 
thofe waves fhould be inflantly levelled. The mo- 
tion they have received will, for fome time, con- 
tinue ; and, if the fhore is not far diftant, they 
arrive there fo foon, that their efFeft upon it will not 
be vifibly diminilhed. Poffibly, therefore, if we 
had begun our operations at a greater diftance, the 
effedf might have been more fenfible. And per- 
haps we did not pour oil in fufticient quantity. Fu- 
ture experiments may determine this. 
N n n 2 
I was* 
