Dynamometer

An instrument for measuring the force of recoil in a small-arm, consisting usually of a spiral spring so arranged as to be compre ed by the butt of the gun in firing. An index shows the number of pounds required to produce a similar compre ion. The instruments now used by the U. S. Ordnance Department are graduated to show the effect of the recoil in foot-pounds or units of work . This sensible change was made at the suggestion of Lieut. Henry Metcalfe of that department. IMG:5166043906965201450_chap line.png: e.