No. 50.] 
311 
To compare this iron with others, it is proper to assume bar No. III. 
as the standard, that having been hammered till of a dull red heat. 
The report already cited furnishes us with abundant data derived from 
experiments, made with the same machine, on other kinds of bar iron, 
in a similar state. Thus we have — 
Strength : 
in lbs. 
per sq. 
inch. 
Iron from Salisbury, Conn., by a mean of 40 
trials, 
58, 
.009 
Sweden, 4 
58, 
.184 
.(( 
Centre Co. Pa. " 15 
58 
.400 
a 
Lancaster Co. Pa. 2 
u 
58 
.661 
u 
Mclntyre, Essex Co. N. Y. [as above] 4 
u 
58, 
.912 
u 
England, cable bolt [E. V.] 5 
il 
59 
.105 
ii 
Russia, 5 
u 
76 
.069 
Hence it appears that the last only is essentially superior to the iron 
of Mclntyre. These are among the best varieties of bar iron in point 
of tenacity. 
The fracture is of a light iron grey colour, silky lustre, and generally 
displays a compact structure. It is worthy of remark that most of the 
fractures took place in directions oblique to the line of tension and mak- 
ing with it, either in the breadth or thickness, one or more angles of 
about 60 degrees each. 
The fibrous structure of the metal was very marked in cutting with 
the cold chisel and was further developed by acids on a part of No. Ill, 
on the surface of which delicate lines were shown traversing a distance 
of several inches. The specific gravity in the annealed state was, it 
appears, increased 1 . 2 per cent by hammer hardening. 
In conclusion it may be observed that as a large and increasing de- 
mand for good iron prevails in the United States, in proportion to the 
increase of finished and accurate machinery requiring supeiior mate- 
rials as well as workmanship, there can be no doubt that any quantity 
which could probably be produced, if possessing the properties of that 
above described, would command a ready market and the best of prices. 
Iron Ores of St. Lawrence and Jefferson Counties. 
It is a fact worthy of particular consideration that the ores of St. 
Lawrence and Jefferson belong to different mineralogical species from 
