Among the French and some others the "tige principle" was employed. It consisted in forcing the base of the ball open so "as to fit the bore and rifle grooves by driving it on a projecting spike in the bottom of the gun attached to the breech, and rising through the charge of powder," as in Fig. 1. For this purpose a countersunk rammer head to fit over the head of the ball had to be used. [Illustration: Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7] In the English Enfield rifle a form of ball was used consisting of a hollow cup or cone in the bored-out base of the ball (Figs. 2 and 3) the action of the powder driving this cup into the ball causing it to expand and take the rifling. Iron cups were used in the Crimea but because of occasionally cutting off and leaving in the bore a ring of lead were discarded for solid wood or papier mache cups (Fig. 4). Figs. 5 and 6 show forms of hollow base balls used by the French and Russians, in which the direct action of the powder on the base caused the sought for expansion into the rifling. The Russians at Sebastopol employed also a fourth principle consisting of two short projections or lugs on the cylindrical part of the solid ball to engage in two grooves cut in the bore of the gun. Its proportions are illustrated by Fig. 7. [Illustration: Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13] The modifications of the preceding forms, shown in Figs. 8 and 9 were used in the Crimea by the Sardinian army which also used a smoothbore musket with solid ball as per Fig. 10. The French army Zouaves used a solid cylindro-conical grooved ball, as in Fig. 11, in a tige rifle. The 1856 Austrian rifle used a solid cylindro-conical ball, "with two deep grooves cut in the cylindrical part such that the parts between the grooves are forced together and outwards, or upset by the explosion of the powder, to fill the bore and the rifle grooves," as in Fig. 12. Fig. 13 illustrates the same principle as used by the Saxon army. [Illustration: Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18] Other forms used at the time by the various Powers are illustrated in Figs. 14, 15, 16, 17, and 18. But it was an open question as to which was the best form, no Power being fully satisfied. It may be noted here that as the breech-loading rifle had not up to this time been sufficiently perfected, all the above bullets were for muzzle loading rifles. Breech-loading arms had been known for over two centuries but were as yet unreliable, clumsy, and generally imperfect. [Illustration: Fig. 19. The Lancaster Gun.]