The monster mortars recently constructed by Mr. Mallet, of separate compound hoops, must be regarded as a triumph of constructive skill. The shell is 30 inches in diameter, holding a bursting charge of 480 lbs., and weighing when charged 11⁄2 tons (3,360 lbs.). Value of shell charged, £25. Weight, without bed, 42 tons. Weight of bed, 8 tons. Total, 50 tons.
Cavalli’s and Wahrendorff’s
In 1846, two rifled cannon were invented, one by Major Cavalli, of the Sardinian Artillery; and the other by Baron Wahrendorff, a Swedish nobleman. Both of these were iron breech-loading guns, having two grooves in order to give the requisite rifle motion to their projectiles.
Experiments to test.
Experiments were carried on at Shoeburyness, in 1850, with these guns. The deviations were always in the direction of the rotation of the projectiles; but they were so variable in amount that no allowance could be made for them in laying the gun with respect to the object. The Cavalli gun became unserviceable after having fired four rounds, by the copper ring or bouche imbedded in the metal of the gun at the bottom of the bore being damaged. The Wahrendorff gun stood well, the wedge resisting more effectually the force of the discharge than that of the Cavalli gun.
Lancaster’s rifle gun.
Mr. Lancaster’s novel invention of applying the rifle principle to cannon, may be described as “a two-grooved rifle in disguise,” having a “gaining twist,” the bore being an ellipse.
Defects of.
The chief defect in the Lancaster gun is the liability of the projectile to jam in the bore, both in loading and firing, the former rendering the loading difficult, while the latter endangers the safety of the gun. In consequence of several of these guns bursting, and also from the anticipated large range with great precision not being obtained from them, the Lancaster guns were removed from the service after the Crimean war.
Sir W. Armstrong.