42 CONTEMPORARY SCIENCE 



forced exigencies of war and Government control. It 

 must be remembered that in the past the great majority 

 of new discoveries and inventions of merit have taken 

 many years sometimes generations to bring them into 

 general use. It must also be mentioned that in some 

 instances discoveries and inventions are attributable to 

 the general advance in Science and the Arts which has 

 brought within the region of practical politics an attack 

 on some particular problem. So the work of the scientists 

 during the war has perforce been directed more to the 

 application of known principles, trade knowledge, and 

 properties of matter to the waging of war, than to the 

 making of new and laborious discoveries ; though, in ef- 

 fecting such applications, inventions of a high order have 

 been achieved, some of which promise to be of great use- 

 fulness in time of peace. 



The advance of Science and the Arts in the last cen- 

 tury had, however, wrought a great change in the imple- 

 ments of war. The steam engine, the internal combustion 

 engine, electricity, and the advances in metallurgy and 

 chemistry had led to the building up of immense industries 

 which, when diverted from their normal uses, have pro- 

 duced unprecedented quantities of war material for the 

 enormous armies, and also for the greatest Navy which 

 the world has ever seen. 



The destructive energy in the field and afloat has mul- 

 tiplied many hundredfold since the time of the Napoleonic 

 wars; both before and during the war the size of guns 

 and the efficiency of explosives and shell increased im- 

 mensely, and many new implements of destruction were 

 added. Modern Science and Engineering enabled armies 

 unprecedented in size, efficiency and equipment to be 

 drawn from all parts of the world and to be concentrated 

 rapidly in the fighting line. 



To build up the stupendous fighting organization, ships 

 have been taken from their normal trade routes, locomo- 

 tives and material from the home railways, the normal 



