In testing cavalry swords, the blade is struck under the same conditions as the bayonet (No 2), is placed in a machine* and pressed on the top while in a vertical position, until it is shortened four inches (No. 1), and must bear a 28lb. vertical pressure without bending. As the result of a investigation instituted by the Government, was recently discovered that in pressing on blade so that it bent first on one side, then the other–a common practice among infantry officers–the fibre of the metal was strained; when, therefore, the vertical pressure test is applied and the blade sprung, a small cross is stamped on the convex side to denote that the sword may be sprung only on that side.
*This device was known as an “eprouvette”.
“Swords: How they are made and something about curious ones” by Frank Lamburn, Pearson’s Magazine, Vol. 2, July to December, 1896