84 AXNTJAL OF SCIENTIFIC DISCOVI&Y. 



Only four shots were fired by Whit-worth's gun. Each bolt was 

 formed of homogeneous metal, hexagonal in form, flat-headed, and 

 weighing seventy-nine pounds. The first passed through the iron 

 plating four and one-half inches thick, and buried itself eleven inches 

 within the wood behind. The second passed through both the plat- 

 ing and the thick timber lining inside, carried away part of an iron 

 knee, and drove a piece of the outer plating half way across the ship. 

 The third shot passed through one of the ports. The fourth cracked 

 a plate, pierced it, and destroyed part of the upper deck water-way, 

 but it did not enter into the ship. 



It was found that the second shot of the Whitworth cannon, which 

 was the only one which penetrated into the inside of the ship, passed 

 through part of a plate that was unsound, and the wood through which 

 it entered was also defective. Whitworth's cannon had the greatest 

 penetrating power. 



From these experiments, with the most powerful rifled guns and 

 solid shot, at two hundred yards' distance, 4l-inch iron plates, having 

 a thick backing of wood, afforded immunity from danger to those on 

 board, although the plates were greatly injured by the firing. 



The effect of Armstrong's 120-pound gun, tried against 10-inch 

 plates, is thus described : " The target consisted of a "shield of iron, 

 the plates dovetailed, backed with massive timber, and braced with 

 iron bars. The 68-pounder made no impression on this bulk, but 

 when it was submitted to an Armstrong projectile of 126 pounds, the 

 destruction was instantaneous. The first shot, at a range of six hun- 

 dred yards, cleaned out one of the 10-inch plates, at the same time 

 carrying away the back support. The next gun fired was one of the 

 ordinary 100-pounder Armstrongs, with a solid projectile weighing 

 110 pounds. The battery was struck in another part, and a breach 

 was made clean through the structure, the fabric itself being so weak- 

 ened as to insure destruction. The third shot, with the same weight 

 of projectile, was directed against another part of the battery, and the 

 result was conclusive, as the whole fabric of the battery, already 

 weakened, came down above the point that was struck." 



With regard to the ultimate effect of artillery against ships pro- 

 tected by defensive armor, Sir William Armstrong unhesitatingly gives 

 his opinion, "that whatever thickness of iron may be adopted, guns 

 will be constructed capable of destroying it." The best ordnance offi- 

 cers of the United States army are also of the opinion that no 

 vessel, however thickly plated with iron, can resist the crushing effect 

 of the immense guns (400-pounders) which they are endeavoring to 

 introduce into our sea-coast fortifications. 



Inefficiency of the Armstrong and Whitworth Guns. Mr. W. 

 Bridges Adams, an eminent English engineer, who has given much 

 attention to the subject of iron-plated ships and the use of heavy 

 rifled ordnance, in a recent communication to "Once a Week" uses 

 the following lan<niao-e : 



"> ^j ^5 



" After all that has been said of the damaging power of the Arm- 

 strong and Whitworth guns against armor plates, it has been stated 

 that the most mischievous weapon is the service 64-pounder of 8-inch 

 smooth bore. There are obvious reasons for this result, and one chief 

 reason probably is, the friction of the rifles, which diminishes the ve- 



