186 A Century of Science 



the reforms of Stein and Scharnhorst introduced 

 the principle of the levee en masse into times of 

 peace, dividing the male population into classes 

 which could be kept in training, and might be suc- 

 cessively called to the field as soon as military exi- 

 gencies should demand it. The prodigious strength 

 which Prussia could put forth under this system was 

 revealed in 1866 and 1870, and since then similar 

 methods have become universally adopted, so that 

 the commencement of a general European war to- 

 day would doubtless find several millions of men 

 under arms. The progress of invention is at the 

 same time daily improving projectiles on the one 

 hand, and fortifications on the other ; we may per- 

 haps hope that some of us will live long enough 

 to see what will happen when a ball is fired with 

 irresistible momentum against an impenetrable 

 wall ! To keep up with the progress of invention 

 enormous sums are expended on military engines, 

 while each nation endeavours to avert war by mak- 

 ing such a show of strength as will deter other 

 nations from attacking it. A mania for increasing 

 armaments has thus been produced, and although 

 this state of things is far less destructive and de- 

 moralizing than actual war, it lays a burden upon 

 Europe which is fast becoming intolerable. For 

 the modern development of industry has given rise 



