. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. larger than the bore, was driven down with a mallet, by Avhich the projecting ribs wereforced into the surface of the ball, so as to keep it in contact with their curvatures, duringits expulsion. Instead of this laborious and insecure process, the barrel being now cutwith only two opposite grooves, fig. 409, and the ball being formed with a projectingbelt, or zone, round its equator, of the same form as the two grooves, fig. 410, it entersso readily into these hollows, that little o
. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. larger than the bore, was driven down with a mallet, by Avhich the projecting ribs wereforced into the surface of the ball, so as to keep it in contact with their curvatures, duringits expulsion. Instead of this laborious and insecure process, the barrel being now cutwith only two opposite grooves, fig. 409, and the ball being formed with a projectingbelt, or zone, round its equator, of the same form as the two grooves, fig. 410, it entersso readily into these hollows, that little or no force is required to press it down upon thepowder. So much more hold of the barrel is at the same time obtained, that instead of onequarter of a turn, which was the utmost that could be safely given in the old way, with-out danger of stripping the ball, a whole turn round the barrel, in its length, can be givento the two grooved rifles; whereby a far more certain and complete rotatory motion isimparted to the ball. The grand practical result is, that better practice has been per-formed by several compa
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Keywords: ., bookcentury1800, bookdecade1840, booksubje, booksubjecttechnology
