408 Mr. Mallet oti the Physical Conditions 



delphia. It was intended, at first, as a 4-pounder, but was only bored for a 3-pounder. 

 This gun was taken at tlie Battle of Brandywine, and is said to be now in the Tower of 

 London.' I believe this is the only gun of which we have any record in this country, as 

 having been used in actual warfare, and, as it appears, with success. The next account of 

 the manufacture and proof of wrought-iron guns in this country is found in the Report of 

 a Board of Officers of the Army, as follows : — 



" ' A 6-pounder wrought-iron gun, manufactured by R. and S. Hunt, anchor makers, 

 was tried at Watervliet Arsenal, in 1832. This gun was fired two proof charges, and 

 forty rounds service charges. At the eighteenth fire the band which held the trunnions 

 slipped ofi", and had to be replaced. After the forty rounds, the gun still remained ser- 

 viceable. The greatest enlargement of the bore was found to be 004 inches, which is 

 more than double that of any of the brass guns proved lately ; from which we may infer, 

 that if all difficulties were overcome, and a complete iron gun made, it would have no great 

 advantage over bronze, as regards its durability. It is understood that these same manufac- 

 turers failed in making other wrought-iron guns. 



" ' Although a proof-gun can be made when the metal is selected with great care, and 

 the fabrication carefully watched, yet, in fabricating them on a large scale, it will be im- 

 possible to take the precautions necessary to insure the perfectness of all these numerous 

 welds. The smallest crack would contain moisture, which would produce oxidation ; and 

 this would, in time, destroy the gun. The Board do not think it necessary to incur further 

 expense in testing this material.' 



" A»ain, says this Report — ' Guns of this material (wrought-iron) were the first used, 

 and they have been tried at various periods, since the first invention of gunpowder, and 

 always without success. 



" ' The first and greatest objection is the difficulty of welding the parts together per- 

 fectly, and the still greater difficulty of determining whether the welds are perfect or not. 

 In the account of a wrought-iron gun, tried at Toulon in 1795, it is stated, that after the 

 gun was broken up, the cascabel and trunnions were found to be held only by a portion of 

 the faces which touched. Three-fourths of these faces showed the effects of rust.' 



" It appears from most authorities that the art of casting guns was esteemed a great 

 improvement upon the more ancient art of forging them, and, whatever may have been 

 the cause, immediately superseded the latter. The cause may have been the vastly dimi- 

 nished cost of the cast-iron guns, or the facility of manufacture, or the opinion of greater 

 security and certainty in the use; or, probably, the combination of all these. Certain it is 

 that the forged guns went entirely out of use. (For the true causes of this, and correct 

 dates of the change, see Note B.) 



" Several accounts of these forged iron guns are given by writers on artillery. Tonsard 

 says, page 168, vol. i. — 'There are at present (1809) on the ramparts of Narbonne two 



