44 ANNUAL OF SCIENTIFIC DISCOVERY. 



a short hundred-pounder, weighing only fifty-three cwt. The distance was 

 one thousand and thirty-two yards, and the projectiles employed were partly 

 solid shot and partly percussion shells. The tower was built of very strong 

 brickwork, the thickness of the walls being seven feet three inches on the 

 land side, and nine feet on the side next the sea. It measured forty-eight 

 feet in diameter at the base, and was upwards of thirty feet high. Like 

 all other Martello towers, it was arranged to carry one heavy gun en lar- 

 lette. The roof, or platform bearing this gun, consisted of a massive vault, 

 of great strength, supported by the walls and by a solid pillar of brickwork 

 occupying the centre of the tower. The chief merit which has been claimed 

 for Martello towers is, that, from their circular form, they deflect all shot 

 which strike them in the curve ; but the accuracy of rifled guns has rendered 

 this advantage of small importance, while the exposed condition of the gun 

 on the top would render it entirely useless against arms of precision. The 

 experiments commenced by a few rounds of solid shot from the forty-pounder 

 and the eighty-pounder, and of blind shells from the hundred-pounder, the 

 object being to ascertain the penetration of these various projectiles. The 

 eighty-pounder shot was found to pass quite through the wall, into the 

 tower, piercing seven feet three inches of brickwork; the others lodged in 

 the wall at the depth of about five feet. Live shells were then fired, and 

 with so much effect, that, after eight or ten rounds from each gun, the interior 

 of the tower became exposed to view. The firing was then suspended to 

 enable the commander-in-chief, who was present, to examine the breach, and 

 also to allow of the execution of a photograph. The fire was resumed in the 

 evening, and continued at intervals on the following day. The centre pillar, 

 supporting the bomb-proof roof, was speedily knocked away, but the struc- 

 tui-e was so compact that the vault continued to stand, and was only brought 

 down by a succession of shells exploded in the brickwork. Nothing could 

 exceed the precision with which these shells were thrown. The broken sec- 

 tion of the vault was itself but a small object to hit; but this was done with 

 such unerring certainty that the very spot selected was almost invariably 

 struck. The total number of shot and shell fired against the tower was 

 one hundred and seventy, of which only a small proportion was from the 

 hundred-pounder. The ultimate result was, that the land side of the tower 

 was completely destroyed, and the interior space filled with the debris of the 

 vaulted roof. The opposite side was also injured, but the mound of fallen 

 materials saved it from destruction. We may infer from these valuable ex- 

 periments that no species of masonry or brickwork penetrable by percussion 

 shells will in future be available in fortification. Nor is it conceivable how 

 wooden ships are to withstand the effects of such projectiles. The hundred- 

 pounded gun used on this occasion is probably the most formidable weapon 

 ever yet produced. Its shell, which weighs one hundred pounds, contains 

 eight pounds of powder; and yet the weight of the gun with which this tre- 

 mendous projectile is discharged is less than that of the ordinary thirty -two 

 pounder, the weight of which is fifty-six hundred weight 



THE NEW WHITWOETH GUN. 



A short time since, the gun invented by Sir William Armstrong was gen- 

 erally acknowledged to have thrown all former achievements in the construc- 

 tion of artillery into the shade; but within the past year a weapon has been 

 brought out by Mr. Whitworth, of England, which, it is claimed, attains 

 results hitherto considered beyond the range of possibility. 



