But this is not all. The fine powder, igniting almost instantaneously, exerts its force in all directions at once, and the barrel may burst at the side before the charge has time to move; whereas the coarse powder, igniting as it does more slowly, first lifts the charge, and then the volume of gas behind it increasing as the powder becomes more thoroughly ignited, sweeps the charge out of the barrel with a velocity increasing towards the muzzle. If time is not given for the charge to receive the full advantage of the expansive force of the generated air, the force is exerted, not upon the charge, but upon the barrel of the gun itself; and that time is necessary for the full development of this force, is proved by the fact that miners mix their gunpowder with sawdust, in order to diminish the rapidity of its explosion and thus get the advantage of its force in the distance: from the miners, then, let us learn how to obtain the greatest benefit from this force, and waste it not. There can be no doubt of the importance of this principle; little progress has, however, been effected from want of scientific illustration; let it be defined like that of steam power, and its adoption will follow as a natural consequence. For several years I have had gunpowder manufactured of various sizes, at the sight of which most sportsmen would express their astonishment. One objection held by sportsmen to the large grained gunpowder is that it does not come up the nipple of the gun; now although I do not consider this at all important, still if the specific gravity of the gunpowder were increased by compressing 1-1/2, 2, or 3 grains of gunpowder into the space of 1 grain, by means of hydraulic pressure, this objection would at once be obviated; whilst at the same time, the powder would be less liable to absorb moisture, or to become friable with age: either of which conditions is incompatible with good shooting. The granulating of gunpowder, to be of the greatest benefit, should be on a uniform principle; the manipulation should be alike in all particulars, but especially in that part of the process which determines the specific gravity. The hydraulic pressure on the cake should be alike in all cases: in fact, the various sizes of grain might be produced from the same cake, and the desired object be thus obtained. But so long as the practice is followed of producing large grain from less condensed cake, the article produced will give unsatisfactory results; and the advantages which might be attained, as my experience denotes, and which would be of the greatest service, alike in sporting, rifle, and artillery powder, will be nullified. Great improvements are yet to be made, especially in the powder used for artillery; whilst range, accuracy, and lessened recoils are points which may be determined with almost mathematical precision.