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III. — On the Physical Conditions involved in the Construction of Artillery, and on 

 some hitherto unexplained Causes of the Destruction of Cannon in Service. 

 By Robert Mallet, Mem. Ins. Civ. Eng. , F. R. S. 



Read June 25th, 1855. 



1 . — Introductory. 



1. IHAT marvellous substance, gunpowder, whose discovery (in Europe at 

 least) we trace to the cell of Roger Bacon, at Oxford, seems within little more 

 than sixty years, to have become known and applied, as an engine of warfare 

 throughout Europe and the East. 



So stimulated was the invention, even of those torpid times, by the surpris- 

 ing nature of the new power conferred, that, but a few years sufiSced to bring 

 cannon to a size at least, that has never been surpassed in modern days, as, for 

 example, in the gun of bronze, cast for Sultan Mahomed for the siege of Con- 

 stantinople, in 1453, of eleven palms in caliber; some of the "confreres" of 

 which still guard the Dardanelles, and a stone shot from one of which nearly 

 destroyed a frigate of Admiral Duckworth's squadron in 1806.* (Note A.) 



For nearly three hundred years, cannon of great caliber, many of which 

 were made of separate staves and hoops of wrought iron, continued the favourite 

 of artillerists throughout Europe ; so that in Queen Elizabeth's and even in 

 Cromwell's time, both here and on the continent, field guns were in use, of a 

 magnitude now scarcely known except as guns of position. 



The opinion, however, that guns of less caliber, in greater number, and 

 served more rapidly, were more efficient weapons, gained ground ; and at the 



• De Tott, Travels, &c. 

 VOL. XXIII. U 



