forward in what he called an improved state. It was, however, again rejected by the Select Committee.

Mr. Greener informs us that " when the explosion takes place the plug is driven home into the lead, and by expanding its outer surface the projectile comes out of the gun fitting as tight as possible, and a line of flight is given to it of corresponding accuracy." In like manner, Captain Minie says, that, "on fire being communicated to the charge, the gases developed act powerfully on the little cup and cause it to penetrate deeper into the bottom of the ball, and in consequence effect the forcing of the latter," as represented by the copy of a French sketch, Fig. 2.

The principles of the system, as here set forth, have been quoted and copied as established facts by many talented writers, solely because they relied on the faith of others.

It may be desirable, before we proceed further, to reflect just for a moment on the nature of the substance of which a rifle projectile is composed.

Lead is a soft, flexible, and inelastic substance. It is malleable and ductile, but inferior to all ductile metals in tenacity. If the atoms (or the exceedingly minute resisting particles) of which it is composed be displaced by a superior force, there is no tendency in them to regain their former positions, as in elastic bodies; they, therefore, remain passively in the new positions they have been forced to take up. The atoms cohere equally in whatever relative situations they may happen to be, and therefore yield to force, or the repulsion of the gaseous particles which are generated by the ignited gunpowder, and shift about among each other almost like the atoms of a fluid. Lead, like wood, may be pierced with a sharp instrument, which will push away the particles to one side and the other, but to no great distance; that portion close to the instrument being rendered only more dense.

If we lay an elongated hollow leaden bullet on a block of wood, with its base outwardsj and then strike it smartly with a mallet, the outer half of the bullet will be expanded, and made shorter, but the other half will not be affected at all. This fact is easily explained, by simply saying that the atoms, or particles of the lead which compose the outer end of the bullet, are driven on the others, before the inertia of the more remote atoms are overcome. The consequence is, that in pushing one another aside the atoms are pushed in all directions, some outwardly and some inwardly, but all then moving rapidly onwards: the inertia of those in front having at last been overcome.

The blow with the mallet is only intense and brisk pressure, suddenly begun and terminated. The action of ignited gunpowder is also pressure, but in a graduated and much more powerful degree. In the latter case, the expansion of the lead would be restrained within certain limits by the sides of the barrel ; and the fore part of the bullet would be altered in shape by the resistance of the condensed air, but only after it had passed up some portion of the tube.

It is said by the advocates of the " Minie" system, that " the cup or plug acts like a wedge, and, on being driven in by the explosion, forces the sides of the cavity outwards." This is a very plausible doctrine on which to build such a system; but it is a very erroneous one; for it is tantamount to saying that the force of the explosion is concentrated on the end of the cup or plug alone, and not let loose with equal force on the entire hinder end of the bullet.

If, for example, we were to insert a wedge into a block of wood, and then take a large mallet, having a cavity in it deep enough to allow the head and body of the wedge to enter, as represented by Fig. 3, we might strike for ever without making the wedge enter deeper into the block, as the face of the mallet would come in contact with the block at the same instant that the head of the wedge came in contact with the bottom of the cavity in the mallet; in fact, the only result would be, that the wood round, the wedge would be rendered more dense by the repeated strokes, and the wedge loosened accordingly.

So it is with the force of the explosion on the end of a " Minie 1" bullet; though, in this case, the entire base of the bullet, plug, and lead gives way together, at the same time, to the expansive force of the powder, showing clearly that the lead does not remain passive while the plug is being driven in.

The most eminent men admit, that, though gunpowder explodes so suddenly as to appear a simultaneous burst of flame, it is, correctly speaking, not so, but merely the rapid ignition and combustion of all the particles; and that a portion of time is necessarily occupied by the flame, however short that portion of time may be, in travelling from the first grains to the last.

It must be then evident that, as a part only of the charge is at first inflamed, the gases which are generated by that part must find a vent before the rest of the charge is completely fired. Now, I have ascertained that the gases engendered by the smallest possible quantity of powder are quite sufficient to overcome the inertia of the entire bullet, and to set it in motion, though not sufficient to press the particles of lead closer on one another. The fourth part of a grain of powder will drive a properly fitting bullet up the barrel a distance of three or four inches; half a grain will drive a bullet up a distance of eight or ten inches; and one grain and a half will drive it out of the barrel altogether. Thus it must be obvious that the gases generated by the first inflamed portion of the charge will find a vent, by simply pushing the unburnt part of the powder, and also the bullet, onwards, while the rest of the powder is being ignited. The gases afterwards, as they increase by the successive ignition of the remaining portions of the powder, act more and more forcibly on the bullet, and cause it to exchange its first, but comparatively slow movement, for one of a very rapidly increasing motion.

This being admitted, it is satisfactory to know that the action of the bullet inside the barrel, as thus described, is also confirmed by the clearest evidence; for, during the course of a very interesting series of experiments, the truth of* this theory was proved, and the facts brought to light also proved, in the clearest manner, the errors of the " Minie" system.

In the course of these experiments, some hundreds of rounds were fired, with various sorts of projectiles, and with different lengths of barrel, into water, clay, and other substances. The first number of rounds fired was from a rifle barrel 2 feet 8 inches in length. Then, after every stage of firing, from 3 to 4 inches were cut off the barrel, until it was shortened to one-half its original length. Two inches at a time were then cut off, until the barrel was shortened to one-fourth; after which, one inch each time was

VOL. II. M

cut off; and then half an inch, until the barrel was shortened close to the charge—a full charge of powder being used at every round. The result showed that, after a certain length had been cut off, the appearance of rifling on the bullet grew more and more indistinct, until not a vestige of it could be traced.

Beginning at the breech end of the barrel, it may be observed that, until the bullet had moved about half an inch, no perceptible signs of expansion had taken place. Then, however, the faintest trace of rifling, like scratches, could be perceived, for about an eighth of an inch, next the base of the bullet. This impression showed itself more and more distinctly, and at greater length, as the bullet proceeded further up the barrel, until it appeared complete all along the cylindrical part. From the proofs which were exhibited in the earlier stages, the compression of the bullet and the expansion of the lead into the grooves must have continued for some time after, though not discernible on the outside of the bullet. This opinion was confirmed by the action of hollow bullets, the cavities of which continued to be more and more contracted as the bullets passed further up the barrel. This was evidently occasioned by the increasing and accumulating pressure of the gases on the hinder end, and the resistance of the condensed air in front of the bullet.

From this it may be seen that the particles of matter which compose the hinder part of the bullet travel for some space of time, though infinitely short, and through some portion of the barrel, at a quicker rate than the particles that compose the fore part; the latter portion continuing to be driven up closer and closer on those which travel before, until the force of the gases has no longer any power to drive the particles closer together, the expansive force of the powder and the velocity of the bullet becoming then nearly on a par.

It will also be seen from this, that, when the bullet is first moved from its state of rest, there is nothing whatever to derange the position of the cup or plug, or to cause it to act like a wedge. As the bullet proceeds, however, the accumulation of the gases becomes a more powerfully propelling force, and consequently the condensation of the air in the tube in front of the bullet rapidly increases its resistance. The result of this is, that as the expansion of the lead into the grooves becomes more and more complete, so also does the