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 distinct 
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- 
Vor. XVIL.—No. 1. 1 
