280 Mr. Mallet on the Physical Conditions 



absorbing recoil, — a necessity by no means self-evident, and to the consideration 

 of which we have adverted. (Note T. ) 



In every respect, then, in which we have submitted them to a comparison, 

 searching and rigid, and that seems to have omitted no important point of 

 inquiry, wrought-iron stands pre-eminently superior to every other material for 

 the fabrication of ordnance. 



But we have also indicated grave difficulties, incident to the forging of large 

 masses of wrought-iron, and hence, apparently insuperable obstacles to the use 

 of wrought-iron, even for guns of the largest caliber at present in use, much less 

 to the extension by its means of the magnitude of our artillery, far beyond any- 

 thing yet attempted, at least in modern practice. 



We proceed, then, to consider how these difficulties can be met, and to 

 determine the conditions under which wrought-iron may be applied to the con- 

 struction of artillery, so as at once not merely to escape, the evils and vast 

 expenditure, of immense single forgings, but also to enable the whole strength 

 of wrought-iron of the best quality, and in its most advantageous state of aggre- 

 gation, to be applied. 



33. — 0/ the proper Construction, in Wrought-Iro7i, of Guns of the largest class. 



267. In the preceding pages it has been shown, that the difficulties of manu- 

 facture in wrought-iron, incident to changes in its molecular condition, com- 

 mence at the point where the rolling process must be abandoned, and give place 

 to forging and hammering (chap. 25). That the frontier of this limit is capa- 

 ble of being largely extended, will not be doubted by practical ironmasters 

 (sect. 215). With existing methods and machinery, however, the production 

 of wrought-iron guns, by means of the rolling process, must stop at about 

 12-pounders, or a caliber of 4'62 inches. 



268. Wrought-iron guns, up to 6-pounders, indeed, may be successfully pro- 

 duced almost by any process of careful forging by hand, with good iron, as the 

 beautiful little Turkish guns, forged at Erzeroum, in the Exhibition of 1851, well 

 showed ; and others, made more than thirty years since, by the author's father, 

 carrying 3 lbs. lead spherical shot, for the boat use of the Coast-guard Service, 



