Here Delvigne picked up the weapon for another trial.  He accomplished far the most important advance yet seen—­an advance relatively as great as Watt’s separate condenser in the steam-engine.  He retained the tige, but he changed the spherical ball into a cylinder with a conical point, as we now have it.  In this he, in effect, reached the ultimatum of progress as regards the general form of the projectile.  He assimilated it to Newton’s solid of least resistance.  That primeval missile, the arrow, had for unnumbered centuries presented to the eyes of men an illustration of a simple truth which scientific formula succeeded, scarce a couple of centuries since, in evolving.  “The bridge was built,” as the old sapper told his commander, “before them picters” (the engineer’s designs) “came.”  The arrow-head describes, as it whirls through the air, a solid varying from a cone only so far as its edges vary from straight lines.  This variation serves to blend the cone with the cylinder formed by the revolution of the arrow-head and the feather.  The difference in length between the ball and the arrow is due to the necessities of the case.  The least practicable length is best for both.  The office of the spirally-wound feather in communicating a rotary motion, and thereby balancing, by an opposite force, the tendency of the missile to swerve in any given direction, is fulfilled by the spiral groove of the rifle.  Of course, the ordinary smooth musket is unfitted to the conico-cylindrical ball.  Discharged from such a barrel, there being nothing to keep the point in the direction of its flight, it soon tumbles over, like an arrow without a feather, and strikes wide of the mark.

Delvigne’s new gun came into use in 1840.  The long matchlocks of the Arabs had been very worrying to the French in Algiers.  It was a common pastime of the Ishmaelites to pick off the Gauls at a distance which left Brown Bess helpless.  Protruded over an almost inaccessible crag, the former primitive instrument would plump its ball into the ranks of the Giaour in the dell below with a precision and an effect hardly requited by victories in the open field or by the cave-smokings of His Grace of Malakoff.  Delvigne’s arm was accordingly supplied to the Chasseurs d’Orleans, and in their hands served the desired purpose.  The matchlock met its match.

Under M. Delvigne’s system, however, the ball was not always well forced into the grooves.  The tige, too, made cleaning difficult:  it often got crooked, and it sometimes broke off.  A M. Tamisier did something toward removing the former difficulty by cutting very shallow grooves on the ball itself.  The other called forth the ingenuity of the now famous Minie, who made his first appearance in 1847-1848, and whose name has attained the same kind of lethal immortality with the names of Shrapnell, Congreve and Rodman.  M. Minie abandoned the tige entirely.  He scooped out the base of the ball