248 Mr, F. A. Abel, on the AppUcation of Science [April 27, 



which can be fired from the old gun before it is unserviceable, scarcely 

 exceeds 1000, while the limit to the powers of endurance of the 

 Armstrong gun is not yet known. Between 5000 and 6000 rounds 

 have been fired from one, without any vital injury to the gun. 



While these important results have been obtained with guns of 

 wrought iron, built up of rings, others, scarcely less valuable, have 

 attended the application of materials, varying in their nature between 

 steel and malleable iron, to the production of light guns, cast in one 

 piece. M. Krupp, of Essen, was the first to produce masses of cast 

 steel of sufficient size for conversion into cannon. A 12-pounder gun, 

 cast of this material, was experimented upon in this country several 

 years ago, and exhibited the most extraordinary powers of endurance, 

 having withstood the heaviest proofs without bursting. Similarly good 

 results were obtained with cast steel in France and Germany, and it is 

 now applied to the construction of the rifled field guns in Prussia. 

 A cast material, somewhat similar in character to this steel of M. 

 Krupp, and to which the name of homogeneous iron has been given, 

 has recently received most successful application in the hands of Mr. 

 Whitworth, not only to the production of the barrels for his rifle-small- 

 arms, but also to the manufacture of his beautiful rifle-cannon. The 

 smaller cannon are cast in one piece, and then forged to the required 

 form. The heavy guns (80 and 100-pounders) consist, however, of 

 cylinders of homogeneous iron — upon which hoops of fibrous iron are 

 forced by hydraulic pressure, the breech-portion receiving hoops of 

 puddled steel. The small Whitworth guns undoubtedly possess the 

 great advantage of simplicity of construction o\er the compound guns 

 just described ; but the present great expense of the material gives 

 the latter the advantage in point of cost. There can be little doubt, 

 however, that the facilities for obtaining products of this description 

 will increase with the demand'; and there appears no reason why the 

 process of Mr. Bessemer, which has recently been applied with great 

 success to the conversion of iron of good chemical quality into excel- 

 lent cast steel, upon a very considerable scale, should not be resorted 

 to for the production, at a moderate cost, of masses of cast steel, or a 

 material of a similar character, of sufficient size for conversion into 

 cannon of all sizes but those of the heaviest calibre, which it will per- 

 haps always be found most advantageous to construct of several 

 pieces, upon the principles just now referred to. 



The improvements effected in the construction of fire-arms have 

 rendered indispensable a careful revision of the descriptions of gun- 

 powder hitherto used, which has already led to the modification of 

 several important points in the manufacture of powder, whereby a 

 greater uniformity in the action of the latter is ensured, and its explo- 

 sion is regulated with special regard to the double work which it now 

 has to perform in the greater number of rifled arms, namely that of 

 propelling the projectile, and of expanding it into the grooves of the 

 rifle. 



The necessity of affording assistance to the removal from the gun 



