nÉprouvette(Gun) An apparatus for testing or proving the strength of gunpowder.
Century Dictionary and Cyclopedia
neprouvetteAn apparatus for testing the explosive force of powders or other explosives. The most simple form is a pistol having the muzzle closed by a plate, which is maintained in position by a spring. When the pistol is fired, the tension of the spring is overcome and the plate is blown back, turning a ratchet-wheel which registers the force of the explosion.
neprouvetteA spoon used in assaying metals.
neprouvetteA short mortar.
Chambers's Twentieth Century Dictionary
nEprouvetteep-roov-et′ a machine for testing the strength of gunpowder.