Eprou-vette.
1. An apparatus for proving the strength of gunpowder. One simple mode is to fire weighed charges and ascertain the range of the balls. A small quantity of powder, a heavy ball, and a short mortar reduce the range within convenient limits. Another is to fire a small quantity beneath a shot attached at the foot of a vertical rod. The latter ascends, and, on reaching its greatest elevation, is prevented from descending by a pawl which engages a rack on the rod. The hight to which the shot ascends determines the strength of the powder. The éprouvette of Regnier is an adaptation of the Sector dynamometer. A small brass cannon is attached to one are and charged with a given quantity of powder. A projection from the other are comes in front of the muzzle, and the parts are separated when the explosion takes place. A cursor over the graduations indicates the point reached by the force of the explosion. See ballistic pendulum. A convenient and portable éprouvette is an instrument shaped like a small pistol without a barrel, and having the forward end of its chargechamber closed by a flat plate connected with a spring. On the explosion of the powder against the plate, the latter is driven forward to a distance proportioned to the strength of the powder, and is retained at its extreme range of propulsion by a ratchet-wheel and spring-click. |
| Eprouvette. |
2. (Metallurgy.) A flux spoon. A spoon for sampling an assay.
