SMOKELESS POWDERS are the mod ern explosives which have replaced black gun powder for use as propellents in guns. Such powders are styled smokeless because they give rise to comparatively little smoke when fired. This is due to the fact that the products of their combustion are practically all gaseous at the temperature of explosion. Black gun powder gives rise to much smoke when fired because 57 per cent by weight of the products of its combustion form solid matter on cooling and, therefore, precipitate rapidly out of the atmosphere. While smokelessness or smoke weakness offers, for many military purposes, the distinct advantage that it permits of a clear atmosphere being maintained during an engage ment; that it delays the enemy in locating the spot from which a shot was fired; and that such powders do not readily foul the bores of the guns in which they are used, these modern powders possess the still more important ad vantage that weight for weight, they are much more powerful than black gunpowder. In con sequence of this we not only by their use are able to impart higher velocities to our pro jectiles and ri secure flatter trajectories, greater ranges and better penetrations than were before possible, but the soldier or the ammunition wagon now carries less weight for the same number of rounds of ammunition or a greater number of rounds of ammunition for the same weight. The earliest experiments with smokeless powder were made by the Eng lish chemist, Howard. in 1800, when he tested the properties of his newly-discovered mercuric fulminate and found that though this violent agent produced little smoke, imparted a low velocity to the projectile and but a slight recoil to the piece, it burst the chamber and demon strated its unfitness to compete with gunpowder as a ballistic agent, though it has found a limited use, when mixed with solid diluents which act as restrainers, in ammunition for parlor rifles, and it is noticeable that when firing this ammunition there is little smoke and a scarcely audible report attending the dis charge.
The next step was •taken when, soon after the discovery of guncotton, in 1845, attempts were made to use this material, in its fibrous condition, as a propellent. These experiments
were made in Germany, France and England, while a very extended series were carried on by Major Mordecai of the United States army, at the Washington arsenel; but the material, owing to its fibrous form and the imperfection in its manufacture, proved too brisant and too irregular in action and it was so unstable as to undergo dangerous decomposition in storage so that it was not adopted. The material had, however, been proved to possess so many valu able qualities that it continued to be the subject of study by many chemists and especially Baron von Lenck of Austria and Sir Frederick Abel of England, the latter devising a method of purification by reducing the guncotton to a pulp or dust. Besides affording a means for the better washing of the guncotton this pulvertilent condition permitted of the dust being formed into grains and a patent was issued to Abel in 1866 for the production of powder by agitating this pulp in a vibrating vessel, with or without a binding material, whereby the pulp was formed into granules of different sizes which were subsequently sorted. The grains thus pro duced were quite soft, easily crushed when dry and readily absorbed water. In 1882 Reid and Johnson of England improved the process by moistening the dried grains with a volatile solvent which on evaporation left the surfaces so hardened as to better resist crushing and the absorption of water from the atmosphere. During this time superficially hardened soft grained powders composed of mixtures of dif ferent cellulose nitrates or nitro-lignins to gether with unnitrated material and nitrates such as sodium or barium nitrates came into use as smokeless sporting powders under the names among others of Schultze, E. C., Brackett's, J. D., and American Wood powders. These powders were, from the method of their manufacture, quite bulky and are, therefore, also classified as bulk powders.