In 1882 at the bombardment of Alexandria we [the British] had 80-ton guns of 16-bore, and in 1886 110-ton guns of 16 ½ -inch calibre.
This powder did not retain its importance long, however, for in the nineties smokeless powder entirely displaced black powder as a propulsive explosive in cannon.
The gases evolved had sufficient power to sever the mass of rock, without being able to force a passage for themselves at the moment.
The game occurred, therefore, here, as in Rumford's experiments, in which neither smoke nor report were perceptible.
The accuracy with which the necessary quantity of powder had been estimated, was proved by the wonderful success of the experiment.A few examples will serve to illustrate the magnitude of such operations, and bear witness to the successful result of* the undertakings. of powder (50 barrels) were placed, in the, middle chamber 7714 lbs. (60 barrels), together, therefore, in the three chambers, 19,836 lbs. The thickness of the mass of rock from the middle chamber was 85.4 ft., from the two others 67 ft.The line of railroad coming from Folkestone, after passing several viaducts, tunnels, and cuttings, traverses the Abbot's Rock Tunnel. At the back of the rock, in a perfectly secure situation, a very powerful galvanic battery was placed under a shed, the covered copper wires of which, extending 1219 ft.The protection against the water is so complete, that a charge may be ignited in this manner after having lain under water for ten days. Brown or cocoa powder gives on explosion a greater quantity of heat and a smaller volume of permanent gases than does an equal weight of black gunpowder; but the larger amount of water vapour in the products of explosion of brown powder have an important influence in lowering temperature.Explosions under water are never accompanied by a report, for reasons already, mentioned; smoke can still less be produced. Edmund Ronalds, Lecturer On Chemistry At The Middlesex Hospital, And Dr. The products of explosion of brown powder undergo considerable dissociation at first, thus lowering the initial pressure in the gun, and subsequent recombination, and so giving sustained pressures as the projectile moves along the bore.After some smaller experiments, at first with 198 lbs., And afterwards four successive times with 49 1/2 lbs.