Old Eprouvette Pendulum
The only real use of these eprouvettes is to check and verify the uniformity of a current manufacture of powder, where a certain course of operations is intended to be regularly pursued, and where the strength, tested by means of any instrument, should therefore be uniform.
Powder Mill
The three ingredients are now ground separately to a very fine powder. The mills which effect this, and incorporate, are so similar, that a description will be given under the head of “Incorporation.” Screening.After being ground in this way, the saltpetre is passed through a slope cylindrical reel, covered with copper sieving wire of 60 meshes to the inch, which, as it revolves, sifts it to the required fineness, being then received in a box or bin underneath. The charcoal and sulphur are likewise passed through similar reels of 32 and 60-mesh wire respectively, and that which remains without passing through, is ground again under the runners.
Robins’ Balistic Pendulum
The only reliable mode of proving the strength of Gunpowder is, to test it with service charges in the arms for which it is designed; for which purpose the balistic pendulums, are perfectly adapted