Relation of the Laws of Mechanics to Perpetual Motion. 175 
by the inventors, and the methods by which we may form an 
opinion whether it has been actually attaine 
Perpetual motion is a motion ees without ceasing, and 
without any renewed application of for A machine may be 
said to possess a principle of perpetual sestians if it continues to 
. move, as long as it is kept in repair; and if it requires no new 
force to be applied to it from without. It-is no part of the requi- 
sition concerning perpetual motion, that the machinery should 
ever be out of repair. If it goes when it is in order, that is all FS 
that is demanded. What is looked for, is not perfection in the . 
construction of the apparatus, but an unfailing moving force z 
i ja 
@ 
ee 
On the other hand, it is required, that this force belong to t 
machine itself; that it be not an application from without. A 
stream of water may run continually. It may be applied to turn 
the wheel of a mill. It may in this way, become a never failing 
moving force. If the mill could be oo always in repair, the 
se 
gee as the» expression is commonly used. The mo moving Pi <8 
is here no part of the mill; it is applied from-without.. What is e vs 
wanted is a orineiple of motion within the machine itself; or af > 
east, so connected with it, as to RCCOAPONY, it wherever it maya’ * 
be remove 
| — It is farther expected that the moving fate sould require BO 
rr. 
new supply of materials to keep it in action. In the steam en- 
gine, the moving force is within: the imachine ; and its agenc’ 
trials and ton is: the” very purpose forgwhich . pes 
ig, wanted. Bering, 
is’ i ich.renders the peek josed: irivention $0 highly # im-i-* 
“Saxtag vagant as the. expectations of mahy afdent i inven- > 
Caste og éppear,; there: enone ason ‘rg esi that this Me fie ey 
vould bev ii 
Ould 
