~Proper powder for expanding bullets.~ ~Powder for hardened bullets.~ ~Consequences of imperfect expansion.~ ~Advantages of hexagonal form.~ “It is most important to observe that with all expanding bullets proper powder must be employed. In many cases this kind of bullet has failed, owing to the use of a slowly igniting powder, which is desirable for a hard metal projectile, as it causes less strain upon the piece, but is unsuitable with a soft metal expanding projectile, for which a quickly igniting powder is absolutely requisite to insure a complete expansion, which will fill the bore. Unless this is done the gases rush past the bullet between it and the barrel, the latter becomes foul, the bullet is distorted, and the shooting must be bad. If the projectiles used be made of the same hexagonal shape externally as the bore of the barrel internally, that is, with a mechanical fit, metals of all degrees of hardness, from lead, or lead and tin, up to hardened steel may be employed, and slowly igniting powder, like that of the service may be employed.” ~Mr. Whitworth’s claims.~ Mr. Whitworth does not lay claim to any originality as inventor of the polygonal system, but merely brings it forward, as the most certain mode of securing spiral motion, but he deserves to be honored by all Riflemen, as having established the degree of spirality, the diameter of bore, to ensure the best results from a given weight of lead, and length of barrel. CONCLUSION. In achieving the important position obtained by the rifle in the present day, it has nevertheless effected no more than was predicted of it by Leutman, the Academician of St. Petersburg, in 1728, by Euler, Borda, and Gassendi, and by our eminent but hitherto forgotten countryman Robins, who in 1747, urgently called the attention of the Government and the public to the importance of this description of fire-arm as a military weapon. In the War of American Independence, the rifle, there long established as the national arm for the chase, exhibited its superiority as a _war_ arm also, in so sensible a manner, that we were constrained to oppose to the American hunters the subsidised Riflemen of Hesse, Hanover, and Denmark. ~Robins’ prophecy.~ We shall close by quoting the last words in “Robins’ Tracts of Gunnery.” “Whatever State shall thoroughly comprehend the nature and advantages of rifled barrel pieces, and having facilitated and completed their construction, shall introduce into their armies their _general_ use with a _dexterity_ in the _management_ of them; they will by this means acquire a superiority, which will almost equal anything that has been done at any time by the particular excellence of any one kind of arms; and will perhaps fall but little short of the wonderful effects which histories relate to have been formerly produced by the first inventors of fire-arms.”