146 THE NEW WORLD OF SCIENCE 



is applicable to explosions of gaseous mixtures as well as to 

 those of ordinary explosive substances and can be employed in 

 the study of the pressures occurring in internal combustion 

 engines as well as those in mines or guns. 



An unexpected feature was the reduction in the cost of ex- 

 plosives in the United States as the war progressed. This is 

 statistically shown in Bulletin No. 56 of the War Industries 

 Board by C. L. Fry, and it was due to the exercise of good 

 management and to improvements in plan and methods which 

 resulted in increased economies in operation and greater out- 

 puts in the face of rising prices for labor and materials. It 

 was also due to the relatively small loss from explosions in 

 manufacture, storage, or transportation. It is true that there 

 did occur explosions of unparalleled magnitude at Black Tom 

 Island, London, Halifax, N. S., where 2367 tons of picric acid, 

 250 tons of TNT and 62 tons of nitrocellulose, or 2679 tons in 

 all, exploded on the S.S. Mt. Blanc; and at Morgan, N. J., 

 where 4225 tons of ammonium nitrate, 370 tons of smokeless 

 powder and 187 tons of TNT were involved; and it is also 

 true a large number of explosions occurred in the industry 

 during the period of the war. But accidental explosions are a 

 feature of this extra-hazardous industry and no true idea can 

 be had of war-time experiences except through a statistical com- 

 parison with peace-time data. This cannot be done in this 

 matter for the United States, since until the declaration of the 

 war the National Government had not exercised any super- 

 vision over the explosives industry. But Great Britain has 

 done so in its domain since 1875, an d H. M. Inspectors of 

 Explosives in the last annual report give a statement of condi- 

 tions from Aug. 4, 1914, to Nov. n, 1918. In this report it 

 appears that there were produced during this time 445,559 tons 

 of explosives and 11,725,000,000 pieces of ammunition and that 

 the average number of persons employed was 61,807, with a 

 maximum of 86,555. Yet, notwithstanding the fact that work 

 was carried on under high pressure, that most of the employees 

 were inexperienced, and that they were supervised largely by 



