The following extract appears in the Estimates of Army Service for 1857-8. “To William Greener, for the first Public Suggestion of the principle of expansion, commonly called the Minié principle for bullets in 1836, £1,000.” ~Wilkinson 1837.~ ~Cork plug 1851.~ Many experiments were made by Mr. Wilkinson in 1837, with balls precisely similar in shape to the Minié, with a conical hole in them, using a wooden plug; and in 1851 experiments were tried at Woolwich with a soft elastic cork, fitting the aperture in the projectile very closely, the compression of which it was conceived would sufficiently expand the cylindrical part, and make it fit the grooves, &c. In some instances it succeeded perfectly, but in many the cork was driven through the lead. ~Gen. Jacobs.~ ~Form of leaden bullet destroyed.~ ~Zinc point to bullets.~ Major-General Jacobs for many years carried on a series of experiments with rifles, and in 1846 submitted a military rifle, with an elongated projectile, for experiments, to the Government at home, and also to that in India. It did not meet with approval in England, and the Company cut the matter short by stating, that what was good enough for the Royal Army was good enough for theirs. There is nothing peculiar in General Jacob’s rifle. He recommends an elongated projectile (plate 20, fig. 14) solid at the base, cast with four raised flanges to fit into the grooves. General Jacobs states, that the desired initial velocity could not be produced with a projectile made entirely of lead, as a slight increase of charge had the effect of destroying the form of the projectile. He also states that the limit of the powers of leaden balls having been attained, it became necessary to find a method of constructing rifle balls, so that the fore part should be capable of sustaining the pressure of large charges of fired gunpowder, without change of form, and retain that shape best adapted for overcoming the resistance of the air, on which all accurate distant practice depends; and at the same time having the part of the ball next the powder sufficiently soft and yielding to spread out under its pressure, so as to fill the barrel and grooves perfectly air tight. And he professes to have solved the problem, by having the fore part of the bullet cast of zinc, in a separate mould. ~Expansion by hollow bore.~ Captain Delvigne, who had been experimenting since 1828, proposed the adoption of lengthened bullets, consisting of a cylinder terminated by a cone, which was subsequently replaced by an ogive. He obtained a patent dated 21st June, 1841, “For having hollowed out the base of my cylindro-conical bullet, to obtain its expansion by the effect of the gases produced through the ignition of the powder.” ~Hollow in case to throw centre of gravity forward.~