MANUFACTURE OF IRON. 
39 
and precarious employment. This of course must have an effect upon the manufacturer ; and 
it is not too much to say, that until this business is conducted with that science and skill which 
are brought to bear upon it in other countries, there will be wanting in our case one important 
element of success. 
A review of the processes of manufacture pursued in some parts of the State will, I think, 
afford another clue to the causes which have served to depress this branch of industry ; and 
as this is one of the most important topics connected with the practical part of this investiga¬ 
tion, I trust that I shall be excused for entering somewhat in detail. 
In the description of the ores of iron which I have already given, it will be observed that 
some of them are nearly pure; that is, consist almost entirely of iron and oxygen in variable 
proportions. Such are many of the ores found in the northern counties, in Orange county, 
&c. As it is only necessary, in order to convert these pure minerals into metallic iron, that 
they should be deprived of the oxygen which they contain, the reduction may be effected in a 
very simple manner. They are accordingly often mixed with a proper proportion of charcoal, 
and subjected to heat in a low or Catalan forge. A part of the carbon, combining with the 
oxygen of the ore, passes off in the form of carbonic acid gas ; while a variable proportion of 
the carbon also combines with the iron, and causes the formation of cast iron, steel, or mal¬ 
leable iron, according to circumstances. If the application of the heat be discontinued after 
the first reduction of the ore, the result will be cast iron ; but as the object in this case is 
usually to obtain malleable iron by a single process, charcoal is added, and the heat continued 
until the cast iron loses its liquidity, and is converted into a loup, as it is termed ; after which 
it is brought under heavy hammers, and formed into bars of various sizes and forms. When 
a peculiar ore, as the spathic iron, is employed, the product of this process is an inferior 
kind of steel. 
This forge is the most humble, and probably the oldest workshop of iron, and was formerly 
in general use where the ores were sufficiently pure to admit of its employment. As it could 
be erected at a trifling expense, it enabled the small capitalist to prosecute the manufacture 
in situations where fuel was abundant, and it often employed the farmer in the intervals of 
agricultural labor. These are perhaps the principal reasons why the forge is so generally 
used in the northern part of the State. But I think it may be safely affirmed that its employ¬ 
ment is wasteful; and as fuel becomes less abundant, and capital increases, it must give place 
to the improved furnace.* 
It is evident from the description of the process which has just been given, that the conver¬ 
sion of the cast iron into malleable iron in the open forge, takes place during the free exposure 
of the former to heat and air in contact with the combustible. There must, however, be great 
waste both of fuel and of ore. Facts prove the correctness of this assertion. If I have been 
correctly informed, three tons of the best ore, such as that from the Arnold mine, are required 
for producing one ton of malleable iron ; and five hours is the average time consumed in carry- 
See Col. Gibbs’ Observations on the Iron Works at Vergennes, Vermont. Bruce's American Mineralogical Journal, p. 80. 
