n THE ROYAL SOCIETY OF CANADA 



cargo sank without exploding. (2) That the products of detonation 

 for this enormous unconfined mass of explosives are the same as those 

 due to small masses in a bomb calorimeter. (3) That the specific 

 heats of gases at high temperatures can be represented by the formula 

 C = A + Bt. 



The cargo of the Mont Blanc consisted of the following high 

 explosives : 



(1) 2,114,000 kilograms picric acid. 



(2) 204,000 kilograms trinitrotoluene. 



(3) 56,000 kilograms gun cotton, 



The decomposition of these explosives is represented by the 

 following equations: 



(1) 2 Ce Hî (N02)3 O H = 8 CO+3 CO2+3 H0+3N2+C. 



(2) 2 C7 Hs (N02)3 =12 CO+5H2+3N2+2C. 



(3) 2C24H29O20(NO2)ii = 24CO+24CO2+17H2+llN2+12H20. 

 From these equations and thermo-chemical data from Marshall's 

 "Explosives" the following approximate results can be obtained: 



Substance Vo Q t° P 



Picric Acid . . 828 



Trinitrotoluene 983 



Gun cotton 859 



Vo is the volume in liters, at 0° and 76 cm. pressure, of the gas liber- 

 ated by 1 kg. of explosive. Q is the heat of explosion in large calories 

 per kg. of explosive. P is the pressure in kg. per cm^ developed by 

 the explosion of 1 kg. in the volume of 1 liter. t° and P were calculated 

 as follows: 



Q 1-033X Vox (273 + t) 

 t = - where C = A + B t P = — 



We thus see that the gases formed had a volume at N.T.P. of about 

 2 X 10^ liters and that the total energy liberated was about 8-7 x 10^^ 

 kilogram-meters. This energy was at first stored in the gases at 

 high temperatures and under enormous pressures. It distributed 

 itself rapidly through the air, water and earth to the surrounding 

 region. All the evidence points to the fact that the air was the prin- 

 cipal factor in the transfer of this energy. Within a radius of four or 

 five miles the earth wave was distinctly felt and was followed by the 

 concussion of the air which caused all the damage. The experience 

 of the writer confirms this point and indicates in a rough way the 

 relative magnitudes of the earth and air shock. At the time of the 

 explosion, I was standing in my laboratory on the second floor of the 



