ON THE 



INTERACTION OF NATURAL FORCES. 



A LECTURE DELIVERED FEBRUARY 7, 1854, AT KOtflGSBERG, 

 IN PRUSSIA. 



A NEW conquest of very general interest has been recently 

 made by natural philosophy. In the following pages I 

 will endeavour to give an idea of the nature of this con- 

 quest. It has reference to a new and universal natural 

 law, which rules the action of natural forces in their 

 mutual relations towards each other, and is as influential 

 on our theoretic views of natural processes as it is im- 

 portant in their technical applications. 



Among the practical arts which owe their progress to 

 the development of the natural sciences, from the con- 

 clusion of the middle ages downwards, practical mechanics, 

 aided by the mathematical science which bears the same 

 name, was one of the most prominent. The character of 

 the art was, at the time referred to, naturally very dif- 

 ferent from its present one. Surprised and stimulated by 

 its own success, it thought no problem beyond its power, 

 and immediately attacked some of the most difficult and 

 complicated. Thus it was attempted to build automaton 

 figures which should perform the functions of men and 



