The High Powered Explosive.—The explosive used is either guncotton, or nitrocellulose, to call it by its chemical name, or tri-nitrotoluene (pronounced ni-tro-tol´-u-en) and which is called TNT for short.
Guncotton is simply ordinary cotton which has been treated with nitric and sulphuric acids; when this is done it becomes highly explosive.
TNT is toluene, a chemical formed of hydrogen and carbon, which has been treated with nitric acid. It is used by the Germans in the warheads of their submarine torpedoes because it is a more powerful explosive than guncotton. Besides it can be melted as easily as lard and poured into the warhead, which makes it an easy, quick, and safe job to fill them. Further, it does not explode easily by shocks when it is transported but it instantly explodes with a detonator.
Courtesy of E. W. Bliss Co.
A BLISS TORPEDO WITH ROTARY COMPRESSED AIR MOTOR
The reason these explosives cannot be ignited by fire but explode when struck a sharp tap is because they are very unstable compounds; that is, they are very easily decomposed into their original chemical parts.
Curiously enough, but by the very discovery of this advanced scientific principle men are now able to make the mightiest, which means the deadliest, explosives that the world has ever known and this makes war a thousand times as terrible now as it was in the olden days when men fought their battles at close range with their ancient lances and cross-bows.
The Detonating, or Firing Mechanism.—A modern submarine torpedo has a diameter of from 18 to 21 inches through the warhead, and this is loaded with from 200 to 330 pounds of guncotton or TNT, as the case may be.
This charge is exploded by a firing pin, or pistol, as it is called. This firing pin goes clear through the charge and into a percussion cap, which sets just back of the charge; the other and front end of the firing pin goes clear through the warhead and has a threaded end on which is screwed what is known as a butterfly-nut.