Physics and Chemistry. 113 
from the Dunnamore mine, is better than any other. 2. Converted— 
with pure charcoal ; it should be carbonized lightly, and the process to 
be stopped when the bars, of the usual thickness, are “‘ scarcely steel 
rn yet so that it will harden with certainty, without an undue 
heat. 3. Sorted—with attention to homogeneous conversion, &c., ac- 
cording to the ordinary rules. 4. Melted—the pot kept covered, and 
not longer than necessary im fusion. 5, Cast—into a large ingot,’so 
as to allow of its bein ng es — es singly, before it becomes ‘re- 
duced to the requisite thinn 6. Rolled—while hot from casting, to 
save a second heating ; it should not nor doubled over, nor sheared and 
fagotted ; the rolling should be conducted at as low a temperature as 
convenient, as it thereby acquires a harder, closer texture, and finer 
n cutting into shape, the substance (if large or of varied 
form) should not be strained, as by boring with “ we ore or straight- 
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provided it be so prepared as to preserve a homogeneous and white ap- 
pearance of fracture when hardened, which is not so easily managed 
as with that of lower carbonization ; but if it be again carbonized more 
than usual, (as razor steel, or above that,) it rather improves ; and 
again an increase deteriorates it as in cast iron, and a further increase 
again soem saa it. In short, in the scale of carbonization there is a 
ession of con ntinually decreasin ng) serge ven of advantage. — 
of grain is affected by many savannas clbotmistuanesp which must 
be considered and nitcaret for in judging of it; andthe most important 
fact is the difference between ‘the appearance in thes hard and soft 
States ; for in the general properties, whether optical, mechanical, or 
magn netical, their omders in any set of samples, is reversed in the hard 
State, independently of the absolate change in each property. The 
Steels should be examined by breaking with a single bend at a file notch, 
iene 3 with a chisel, bending back, &c., change the appearance.) 
Am pe of 6 or 10 lineal power is better than any other power 
for comin it.’ The general properties, without going into deiailed 
description, should be as follows, the terms being comparative with other 
samples of less — = not at ni with the hard or —_ states ces “ 
e steel : 
+ ha 
tia 
a soft sta Ina hard pia vi pee! 2 is 
Sion appearance seething Uniform white. dl 
Rather a large grain ;co ompared with rar A ‘smaller grain. ‘than itv was hate ne 
zor steel, (or finer if much rolled.) before. Rounded 
Rather i alaee in ‘Ron se elie aca aren, ns indi- 
~ grain, u ndedecrystalli- © 
ee aks y vidually, distinct, ma oa Seta 
Close eerie ly close." 
texture, without eave. Di trict 
Psa h for Britie, hard. 
erably before. magnet- Ditto. 
ae duce a rt agi more freely Retains magnetism well and sound tty, 
_ steels. 
- Seconp Serizs, Vol. It, No. 7. San. ‘ 1847. Pa 
