The tracer bullet is interesting as an example of yet another armament feature in which considerable research was required, and therefore much time elapsed after the outbreak of war before it could be used. Although most readers will remember this bullet, very few will have troubled to become acquainted with its details. The object was to design a bullet specially suited to attain an individual objective, such as in aircraft combat, where great speed of both opponents made it essential to record a hit in minimum time, and with the least number of shots. In such combats, bullets not attaining their objective were wasted, whereas in many forms of land warfare there was a very good chance that a second, unsighted objective would be attained, and also more opportunity to retrieve an error. The idea, therefore, was to make a visible or tracer bullet which would enable very rapid adjustment to any initial errors. The fact that the bullet was visible much facilitated the task of firing from a moving weapon at a moving object, and tracer bullets were therefore mainly employed by aircraft machine-gunners, being inserted at intervals in the belt feed. The shell of the bullet was of copper-nickel, containing the lead core and a rear chamber with a small aperture to the atmosphere. In this chamber was a chemical mixture which burnt with such a bright light that it was even visible in strong sunlight and against the worst backgrounds. One such mixture contained barium peroxide and magnesium, which was ignited from the cartridge flame.
The tracer bullet, the incendiary bullet, and the armour- piercing bullet, and their combinations, were all matters of investigation, requiring many months of laboratory and field work, with the further delays in reaching and standardising the new processes of steady bulk production.
We could go on describing the production characteristics of other forms of normal armament and their accessories, but we have probably dealt with sufficient for our immediate purpose. We have certainly not excluded any type of sufficient importance to interfere with the stability of a disarmament scheme by its own individual use apart from other weapons, nor have we consciously excluded any important type which is not subject to the same general conclusion as regards conversion lag. It remains to point out what must, in fact, be clear to all--that you cannot