4400 32 + ------------- = 6347° Fahr. = 6808°·2 absolute, 0·190 × 3·667
the mean specific heat of the gases being 0·190; whence it will be seen that the temperature has been increased
According to the law of thermo-dynamics, therefore, the pressure under the foregoing conditions will be 5124 × 13·01 = 66,663 lb. = 29·8 tons to square inch. So that, under the conditions assumed in this case, the pressures developed by incomplete and by complete combustion are as 29·8 to 77·3, or as 1 to 2·59.
Similarly, when hydrogen is burned to water, the temperature of the product will be, as shown in a former paragraph, 16,049 Fahr. = 16510·2 absolute; and the pressure will be
16510·2 22,830 × ------- = 720,286 lb. = 321·1 tons to the square inch. 523·2
It will be observed, from a consideration of the foregoing facts, that a very large proportion of the force developed by an explosion is due to the heat liberated by the chemical reactions which take place. And hence it will plainly appear that, in the practical application of explosive agents to rock blasting, care should be taken to avoid a loss of the heat upon which the effects of the explosion manifestly so largely depend.