388 Mr. Mallet on the Physical Conditions 



lbs. per Square Inch. 



American hammered Iron, from different bars, — 



Bridgewater, Mass., first specimen, 58,488 



,, „ second „ 40,338 



Mean 53,913 



" ' Recapitulation of all the kinds of wrought-iron tried, showing the actual and the 

 proportional cohesive power of each at one view : — 



lbs. per Square Inch. Proportional Strength. 



Russia iron 62,644 10000 



TBanke's, . . . 56,532 -9024 



English iron, | l^^ Moor, . . 56,103 -8955 



American, 53,913 •8605 



Iron of the r Original bars, . 46,086 -7356 



" Princeton's" < As in the gun, . 38,595 -6161 



gun. I Same, re-worked, 52,521 •8383 



" 'The results of this examination appear to show, that the iron used in forging the 

 " Princeton's" gun was originally of an inferior quality, having only about three-fourths 

 the strength of English iron. It appears, also, that the miginal strength of the iron is 

 coiisiderahlij imjMired by the i^rocess of welding it into so large a mass as that lohich formed 

 t]tegun,—the strength, before and after welding, being about as 6 to 5.' 



" In the opinion of the General Committee, the specimen of English iron, used in this 

 comparison, is of a good quality, while that of the American is not of the best kind. 



" The following are the results of experiments made at the Hall of the Franklin Insti- 

 tute, in reference to the quality of the material of the gun : — 



" I. — Experiments with the metal, in the state in which it existed in the gun : — 



lbs. 



First specimen, cut from position marked h, near the bore of the gun, being 

 part of the shaft made of the longitudinal bars; strain, lengthwise of 



fibre, broke with a tension on the square inch of 38,400 



Second specimen, from the same place, circumstances same, broke with less 



than 25,800 



Another specimen, from position marked h, near the outside of the gun, 



across the fibre, 31,100 



Second specimen, from same place, circumstances same, less than . . . 31,100 

 Third specimen, continuation of the preceding, towards the breech, . . 41,400 

 Specimen in tangent to circle of bore across fibre of shaft, made by the lon- 

 gitudinal bars, from position marked L, broke with, 23,700 



