|
| Maximum |
| Distance |
| at which |
| Detonation |
| occurred. |
| CM. |
| |
Gun-cotton | 10 | Nitro-glycerine 86.5 nitro-cotton
| | 9.5, camphor 4 per cent.
Explosive gelatine | 20 | NH_{4}NO_{3} 5 parts,
(camphorated) | | C_{6}H_{4}(N0_{3})_{2} 1 part.
Judson powder, R.R.P. | 25 |
Emmensite (No. 259) | 30 |
Rack-a-rock | 32 | KClO_{3} 79 parts,
| | C_{6}H_{5}(NO)_{2} 21 parts.
Bellite | 50 |
Forcite No. 1 | 61 |
Kieselguhr dynamite No. 1 | 64 | 75 per cent. nitro-gycerine.
Atlas powder No. 1 | 74 |
__________________________|____________|_________________________

CHAPTER IX.

_DETERMINATION OF THE RELATIVE STRENGTH OF EXPLOSIVES._

Effectiveness of an Explosive--High and Low Explosives--Theoretical
Efficiency--MM. Roux and Sarrau's Results--Abel and Noble's--Nobel's
Ballistic Test--The Mortar, Pressure, or Crusher Gauge--Lead Cylinders--
The Foot-Pounds Machine--Noble's Pressure Gauge--Lieutenant Walke's
Results--Calculation of Pressure Developed by Dynamite and Gun-Cotton--
Macnab's and Ristori's Results of Heat Developed by the Explosion of
Various Explosives--Composition of some of the Explosives in Common Use
for Blasting, &c.

~The Determination of the Relative Strength of Explosives.~--Explosives
may be roughly divided into two divisions, viz., those which when exploded
produce a shattering force, and those which produce a propulsive force.
Explosives of the first class are generally known as the high explosives,
and consist for the most part of nitro compounds, or mixtures of nitro
compounds with other substances. Any explosive whose detonation is very
rapid is a high explosive, but the term has chiefly been applied to the
nitro-explosives.

The effectiveness of an explosive depends upon the volume and temperature
of the gases formed, and upon the rapidity of the explosion. In the high
explosives the chemical transformation is very rapid, hence they exert a
crushing of shattering effect. Gunpowder, on the other hand, is a