Manufacture of Steel. 113 



it to those engaged in other branches of manufactures. The domes- 

 tic manufacture of steel is a subject of great importance to the United 

 States. Whoever labors to improve it, deserves well of his country, 

 and we heartily wish him success. 



Trials of Mr. Clarke's Steel. 



The results of our examination and trials of this steel are as fol- 

 lows : — 



The steel looks well in the bar. The fracture presents in a high 

 degree, that appearance which we have been accustomed to consid- 

 er as indicating a superior quality of steel. 



It is often the case with steel as high as this, that it will not " bear 

 the fire well," as the workmen term it ; that is, before the heat is suffi- 

 ciently raised, it will begin, (perhaps by the extrication of gas,) to ex- 

 foliate or puff up and become spongy, which so much affects its pow- 

 er of conducting heat, that combustion will commence on the surface 

 before the interior parts are sufficiently heated. Mr. Clarke's steel is 

 remarkably free from this difficulty. 



A cold chisel was made of it, which stood severe usage, as well as 

 those made of English steel. 



In attempting to draw a piece of it for a ramrod, three disdnct 

 flaws were formed before the drawing was completed. The attempt 

 therefore failed. In making rods from the English steel, we do not or- 

 dinarily find more than that number of flaws in drawing a hundred rods. 



After making several trials for the purpose of ascertaining the pro- 

 per temper to be given to it, we made a main-spring of it, which 

 was tempered as nearly as possible, according to the result of those 

 trials. This spring, on being put into a lock, broke at about one 

 third of the ordinary degree of tension. The fracture indicated that 

 it had fire-cracked in hardening. From this cause we usually lose 

 from two to five per cent, of the springs made of the English steel. 



From these experiments our conclusion is, that this steel would 

 not answer for rods ; but we are not certain that it would not answer 

 for main springs, if the best method of tempering it were more per- 

 fectly ascertained by further experience. 



In the course of the last four years, we have made trials of several 

 specimens of American steel at the request of different persons who 

 have attempted the manufacture of it, and to a greater or less extent, 

 have uniformly found the same difficulties with it. We however, on the 

 whole, give the preference to Mr. Clarke's steel, over any we have seen. 



Vol. XVII.— No. 1. 15 



