414 Mr. Mallet on the Physical Conditions 



first-cost of wrought-iron cannon is the same as that of bronzep], and more than six times 

 that of cast-iron. Bronze guns, it may be farther remarked, after being too much worn 

 for service, can be easily recast, whereas the old wrought-iron is useless for refabrication, 

 and of little value in such large masses for any purpose. 



"In regard to the experience of European powers on this subject, it may be stated 

 generally, that the use of wrought-iron, as a material for cannon, has been attempted in 

 Europe repeatedly, without success, from the invention of fire-arms to this time. The 

 cannon of small size have succeeded better than large ones ; indeed, there is no known 

 record of a wrought-iron gun for heavy shot proving satisfactory [?] . The works of European 

 writers on artillery abound in notices of wrought-iron cannon, of dates of manufacture 

 extending back from the present century to the remotest periods of their use. 



" Frequent instances of accidents from their bursting are mentioned, and they have 

 never been successfully manufactured on a large scale. Meyer, in his work entitled, 

 ' Experiments in the Fabrication and Durability of Cannon, both Iron and Bronze,' 

 edition of 1834, says : — ' It is certain no experiment in artillery has been so often unsuc- 

 cessfully repeated and abandoned as the fabrication of wrought-iron cannon ; and even at 

 this time we are but little further advanced in it than at the beginning.' And Gassendi, 

 in his ' Aide Memoire d'Artillerie,' edition of 1819, condemns the use of wrought-iron for 

 the manufacture of cannon entirely. Herewith are submitted extracts from different 

 writers, containing a chronological history of wrought-iron cannon, and remarks on the 

 use of this material for their fabrication." 



These extracts are omitted, as a much more complete chronology of the subject is 

 contained in Notes A and B. 



" In regard to ' the relative strength and utility of wrought-iron and cast-iron cannon,' 

 the former having been already noticed, it may be stated, in reference to the latter — 



" First, — As to the strength. Cast-iron is of so many different qualities and kinds, and 

 so variously affected by different modes of fabrication, that it is impossible to speak of the 

 strength of cast-iron guns generally. It is known, however, that by careful attention to the 

 selection of the metal, to its treatment in the furnace, to its proper distribution throughout 

 the body of the gun, in relation to the force exerted on its different parts, by the discharge, 

 to its gradual cooling after being run into the moulds — in a word, to all the manipulations 

 connected with its manufacture, and not so severe a proof, as to strain or weaken the 

 cohesion of the particles, cast-iron gvms, sufficiently light for siege, sea-coast, and garrison 

 service, may be made, the use of which, with full charges, will be safe for at least one 

 thousand fires. But although the practicability of making good and safe guns of cast-iron 



