254 THE NEW WORLD OF SCIENCE 



mounting at the rate of 832 per month, while England was 

 making them at the rate of 802 and France at the rate of 1138 

 per month ; and we were making machine guns and automatic 

 rifles nearly thrice as fast as England and more than twice as 

 fast as France. 



How rapidly we increased our production of ammunition is 

 shown by the fact that about one-quarter of all the high-ex- 

 plosive 75-mm. shells, and nearly 40 per cent, of all the adapters 

 and boosters for them which we machined up to November 

 ist, 1918, passed inspection in October, 1918. 



By the end of the war we had at least 42,000 workmen en- 

 gaged in the manufacture of great guns, including their car- 

 riages and fire-control apparatus. Though, because of our 

 initial lack of preparation, our Army Ordnance Department 

 sold to our allies much less than half the ordnance that it 

 bought from them, yet our country sold them five dollars' worth 

 of ordnance and materials for conversion into ordnance and 

 munitions for every dollar's worth we bought from them. We 

 may well consider how far the resulting adverse trade balance 

 of our allies represents a normal debt, and how far a pound 

 of flesh from next the heart. Before our belated entry into 

 the war we knew that they needed these arms to defend us 

 as well as themselves from annihilation. If I arm a watchman 

 to defend both himself and me, which is the debtor? Should 

 he alone pay for the arms which he uses in our common de- 

 fense, while I remain at home in supposed safety? 



Simplification of Cannon Making. The manufacture of 

 cannons was materially hastened and their quality improved 

 at the same time by decreasing greatly the amount of forging 

 which they undergo. This seems at first a most uninteresting 

 and purely administrative measure, but on examination it turns 

 out to be due to basic physical considerations of very great 

 interest, which might well escape attention. We ask at once 

 " Why are cannons forged at all ? Why do we follow the 

 tedious and expensive plan of casting the molten steel in a 

 very large ingot, as the crude mass into which the steel is first 



