24 CARNOT. 



day, beyond the limits of science), the movement effected 

 would be hardly the breadth of a hair. 



If the ideal machine, the machine endowed with all 

 imaginable perfections, adds nothing to the force which 

 puts it in action, at any rate it takes nothing away from 

 it ; it transforms the effects by rigorous equivalents. It 

 is not thus with a real machine ; in this case the power 

 and the resistance communicate with one another by 

 means of pieces which we had supposed inflexible, and 

 which are not so ; by means of chains and cords whose 

 roughness cannot but be injurious ; the movable parts, 

 moreover, turn in collars or sockets where great friction 

 takes place ; all these causes united absorb in pure loss 

 a very noticeable part of the motive force ; so that the 

 effect of a machine must always be inferior to that which 

 would have been engendered by the power acting directly 

 on the resistance. 



These results of theory, which are, moreover, com 

 pletely confirmed by experience, yet allow that, under 

 certain points of view, some particular machine may be 

 recommended without paradox ; that it may be useful 

 and often even indispensable. For instance, considerations 

 of solidity or ornament necessitate the carrying to the sum 

 mit of certain edifices blocks of stone or marble whose 

 weight is beyond the strength of the most vigorous work 

 man ; suppress the windlass and analogous machines, 

 and one man will no longer be able to execute the work 

 which the architect has conceived ; it will be necessary 

 to unite the strength of thousands of arms at the same 

 point; the narrowness of space will prevent that; the 

 character of grandeur will disappear from all the monu 

 ments of architecture ; the triumphal arch, the palace, 

 will only be constructed, like the humble cottage, of 

 little rough stones. 



