Page:Miscellaneous Papers on Mechanical Subjects.djvu/83

 RIFLED FIRE-ARMS.

are rifled to give rotation to the projectile round its axis of progression, in order to insure a regular and steady flight, the first thing therefore to be considered is what are the best mechanical means of effecting this object.

It would be foreign to our purpose to consider any of the various plans which have been proposed for furnishing the projectile itself with vanes, wings, grooves, or other configurations intended to give it rotation during its passage through the air. The only practical method hitherto adopted has been to make the barrel of a fire-arm of such a shape in its interior, that the projectile while being propelled from