Relation of the Laws of Mechanics to Perpetual Motion. 179 
3. No combination of machinery produces any real increase of 
force. ‘This is the fact with respect to each of the instruments 
called mechanical powers taken singly ; and it is equally true, in 
whatever way they may be combined with each other. The use 
of all apparatus of this kind is not to create force, nor to increase 
it, but merely to apply it. It is true, indeed, that a mechanical 
power may be so contrived, that a small wel ht may raise avery. 
great one. But it will raise it a very short distance only. Ifone 
is a thousand times as large as the other, the latter must descend |. 
a thousand feet to raise the former one foot. So that the mo- — 
mentum of the large body is no greater than that of the smaller 
one. There is, therefore, no increase of force obtained. 
é or two cautions are necessary, however, in estimating the 
wotthilin of the power and the weight. In the first place, the 
velocity is to be reckoned ¢n that direction in which the moving 
force of the body acts. Thus if a body moves down an inclined 
plane, the moving force is gravitation, which acts towards the .. 
center of the earth. The velocity, when we are calculating the . 
equilibrium, must be estimated in this direction.’ In the second © 
place, there must be brought into the account, that part.only of - 
the power which is concerned in producing the effect. Ifa weight - 
act obliquely on the arm of a lever, a part of its force vie 
lost. -This must be thrown out of the estimate. 
With these qualifications, we shall find, that apne oe li-” 
| cated may be the apparatus, the power will be to ee 
of force 
oh NW AS 
WES & 
equilibrio, as the velocity of the weight. to tn wd 
: ‘power. As their momenta are equal, there i is no increase « 
+ Lari . = bepress - This is a proposition, 
which one in pursuit of perpetual ead 07 
brought fally ra belive till he has learhed it b tifyin 
— He expe s, by some ‘peculiar ahiainperient of, his 
ers, a Aes ad ‘and eelined planes, to 1 appear 
a. t i onl'y-A" cor maxim, intended to: eee é 3: 
ar a: ch wade Richy He seeks after mod 
nuch:as possible, from those 2 
nm the grand secret, th some. 
i “> ppsition : Uy peg bithero escaped. ob 
_ Bthe effeoge Sicompnly to ese the 
% Pk Re mechanics; no’ co to pons 
| 
ed, te mens . 7 
% 
= 
eed oem motion in 
a} hough heemy acknowledge, 
- peth ne neha sitself poate force, yet he far 
considers that ga l + i 
, and. that, if he can 8 
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