550 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



sity made; but to make a gun that is to be bored out, exposing more snr- 

 face to critical examination, and to the searching test of powder, is of 

 questionable propriety, to say the least. The effect of powder upon the best 

 and most minute welds of even the best quality of wrought iron is shown 

 in a marked manner by the evidence of Mr. Anderson, superintendent of 

 the voysil gun factory, for Armstrong guns, before the select ordnance com- 

 mittee of the English House of Commons, as follows: 



49. Question 1G76, by Sir Frederick Smith: Will you be kijid enough to 

 state to the committee how the failures take place when your guns are 

 under proof? 



50. From what I have already said, you will see the tendency is for us 

 to wish for a hard metal, in order to avoid indentation; but the harder we 

 get it, the greater is the liability for non-welding. The chanccffe are, when 

 the iron is hard, that some portion is unwelded, and then the powder acts 

 upon that part of it, and very soon makes it appear worse, and renders it 

 necessary to withdraw the interior of the gun, and put in another lining. 



51. 1671. Will you explain to the committee how the unwelding can 

 take place? 



52. If you were to see the process performed, and to see it even in the 

 turning lathe, you would think it was perfect; but the powder soon shakes 

 it up, ajd shows the smallest defect. 



53. 1680. In what part of the bore is the defect first seen? 



Most in the vicinity of the bullet; the pressure of the gas indents the 

 iron (see paragraphs 33, 34, 35, of this paper.) We always leave the bore 

 a little smaller, so as to enable us to enlarge it to the proper size by boring 

 out afterwards. 



54. 1690. Do you consider that it is possible to find any iron capable of 

 resisting a heavier charge than that which has been lately used in the 300- 

 pound guns? 



|f> 65. No; we could not get a better iron for gun material. We could get 

 it harder (i. e., with greater tensible strength), but still not better as a 

 whole, at the present time, than what I have ah-eady stated. 



56. It will be discovered by a careful study of the subject that this fail- 

 ure to comprehend the effect of heat upon the gun, when it is being fabri- 

 cated, as well as when it is used, is the foundation of all the errors and 

 misapprehensions connected wMth this intricate subject. If it were not for 

 the unequal heating or cooling, the strongest and most rigid metal would 

 make the strongest gun. 



57. In England, as in this countrj^, the fabrication of guns is intrusted 

 to a class of men educated in college in the higher sciences, so far above 

 the ordinary practical pursuits of life, that they have overlooked the real 

 diflSculty of the subject. Tiiey arrogate to themselves all knowledge on 

 the subject they have in charge, and all the emoluments growing out of 

 Buccess. Hence practical men, who might have advanced the science of 

 ordnance, have been deterred from giving attention to it. For myself, I 

 find hearty corroboration of my views from the superintendents, foremen, 

 and workmen in foundries, and have no doubt that I should get certificates 

 from every skillful worker of metal on an extensive scale in the United 

 States as to the correctness of my theories, and from each the relation of a 



