Early gunnery experiments

At the time when the Crimean War broke out, the attention of many persons was directed to the state of our armaments, and I, like others, fully shared the interest which was excited. The question of elongated projectiles had been previously considered, but we were quite unprepared at that time with rifled ordnance. In thinking over this subject, it occurred to me that it would be possible to give rotation to a projectile, when fired from a smooth-bore gun, by allowing a portion of the powder gas to escape through longitudinal passages formed in the interior, or on the outer surface, of the projectile. If such passages terminated in the direction of a tangent to the circumference of the projectile, the tangential emission of powder gas (under enormous pressure) would act as in a turbine, and produce a rapid rotatory motion of the projectile. It may at first sight appear that such a method would be attended with great loss of power, but it must be remembered that in any system of rifled ordnance enormous energy is required to revolve a heavy projectile, to say nothing of the power lost by the friction of the studs in the rifled grooves.

It was under the impression that my invention would enable all existing smooth-bore guns to be at once utilised for discharging elongated shells and solid projectiles, and would at the same time solve a problem of great national importance, that I applied for and obtained a patent on the 24th November, 1854. It will be evident that this system of giving rotation to elongated projectiles might, in some eases, have rendered it desirable to hoop, or otherwise strengthen, existing guns, or to construct new guns of greater strength than those then in general use. But the main question was: Can rotation be given efficiently without the manifold disadvantages of rifling? As a matter of fact, I submitted my plans to the War Office, and, after some considerable delay, I was informed that the invention was not of a nature to be used, or experimented upon, by the War Department. Our War Department had at that time no artillery that could throw an elongated projectile; yet with that ever-ready tendency of our military authorities to pooh- pooh every proposition of the civil engineer, my scheme was set aside, and so simple and inexpensive an experiment as the manufacture of half a dozen cast-iron elongated projectiles was refused. Nothing more than this was required, as they had plenty of cast-iron guns in store, and all other needful appliances. I, however, was determined to ascertain for myself whether I was right or wrong in my belief that rotation could be effected simply by the emission of a portion of the gases in the manner described, and for this purpose I made a simple cast-iron gun of 5 1/2 in. bore, and of short length. As I had no butt to fire into, I thought it best to use the gun as a mortar, and discharge it into the air at an angle of 45 deg. of elevation; by using small charges I ensured the projectiles falling in my own grounds near Highgate, where I was then living.

The gun was a simple bored cylinder, cast all in one piece with the framing, which, with its wide base- plate B,* served for a carriage, as shown in the section in Fig. 33. The projectiles weighed 60 lb. each, and were turned and truly fitted to the bore of the gun; the form of projectile employed is given at D, which is an elevation showing by dots one of its longitudinal passages with the tangential aperture at d.* With this simple apparatus I commenced my trials, using extremely small charges of powder, which I gradually increased until the projectile reached an estimated altitude of 200 ft., and fell to earth well within my own grounds. In order to clearly see that the projectile revolved during flight, I bored on its opposite sides two holes, 3/4 in. in diameter and 2 in. in depth, in a radial direction, as shown in section at e e. These holes were tightly rammed with damp meal powder, and on firing the gun (as I used no wad) the powder became ignited and fizzed away like a squib. Standing beside the gun I saw the shot soaring, with its flat end presented to me, and by its rapid rotation the two squibs formed a sort of revolving Catherine wheel, which burned until after the shot had fallen to earth, thus proving beyond all controversy that the projectile both rotated and went end-on during its whole flight. But still I was no nearer my object, and might for ever have remained as I was, but for an accidental circumstance which I will relate.

Some few months after these preliminary experiments were made, I happened to be one of a house party, staying with Lord James Hay at the residence of his married daughter, Madame Gudin, in the Rue Balzac, Paris. Our host gave a farewell dinner to General Hamlin, and a number of other French