PERPETUAL MOTION. 327 



has always cost me much time and trouble. Unhappily 

 my efforts have rarely been attended with success, 

 and only complete failure and the bitterest self-inflicted 

 distress occasionally brings these inventors to a per- 

 ception of their errors. 



There are specially two inventive ideas, which 

 have misled and frequently also ruined innumerable 

 people, otherwise fairly gifted and even remarkably 

 clever in their own sphere of activity. These are 

 the inventions of so-called perpetual motion i. e. of 

 a self-acting work -performing machine, and that of 

 the flying -machine and the manageable balloon. One 

 might have thought, that the knowledge of the law 

 of the conservation of energy had already so far 

 penetrated the popular mind, that creating force out 

 of nothing would have come to be considered as con- 

 trary to nature as the production of matter, but it 

 seems that generations must always pass away before 

 a new fundamental truth is universally regarded as 

 such. If a man is once possessed by the unhappy 

 delusion, that he has found the way to construct 

 working machines by mechanical combinations alone, 

 he has become the victim of a generally incurable 

 mental ailment, which defies all teaching, and even 

 the most painful experience. Almost the like holds 

 good of the endeavours to construct flying-machines and 

 manageable air-balloons. The problem itself is indeed 

 for every mind possessing a slight mechanical training 

 a very simple one. It is indubitable that we can con- 

 struct flying-machines according to the pattern of flying 



