STATEMENT OF DYNAMIC PROBLEM. 223 



part not in one way merely, but in many ways. It is here as 

 with the weaver's web, 



Where a step stirs a thousand threads, 



The shuttles shoot from side to side, 



The fibres flow unseen, 



And one shock strikes a thousand combinations. 



Now it is clear that if by any means we could succeed, as 

 the above American professed to have done, by mechanical 

 forces, to excite chemical, electrical, or other natural pro- 

 cesses, which, by any circuit whatever, and without altering 

 permanently the active masses in the machine, could produce 

 mechanical force in greater quantity than that at first applied, 

 a portion of the work thus gained might be made use of to 

 keep the machine in motion, while the rest of the work might 

 be applied to any other purpose whatever. The problem 

 was, to find in the complicated net of reciprocal actions, a 

 track through chemical, electrical, magnetical, and thermic 

 processes, back to mechanical actions, which might be followed 

 with a final gain of mechanical work ; thus would the perpet- 

 ual motion be found. 



But, warned by the futility of former experiments, the 

 public had become wiser. On the whole, people did not seek 

 much after combinations which promised to furnish a perpetual 

 motion, but the question was inverted. It was no more 

 asked, How can I make use of the known and unknown rela- 

 tions of natural forces so as to construct a perpetual motion ? 

 but it was asked, If a perpetual motion be impossible, what 

 are the relations which must subsist between natural forces ? 

 Everything was gained by this inversion of the question. 

 The relations of natural forces rendered necessary by the 

 above assumption, might be easily and completely stated. It 

 was found that all known relations of force harmonize with 

 the consequences of that assumption, and a series of unknown 

 relations were discovered at the same time, the correctness of 



