Part I. Report of progress in 1869, by J. S. Newberry, chief geologist. Part II. Report of progress in the second district, by E. B. Andrews, assist. geologist. Part III. Report on geology of Montgomery County, by Edward Orton, assist. geologist.

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process at a certain point, to leave the fluid metal in the condition of
cast steel. Upon trial the injection of even cold air into molten iron,
instead of chilling it, as many predicted, produced active ignition and
intense heat. This was the germ of the famous Bessemer process for the
manufacture of steel, a process by which fully one-half of the steel now
made is produced, and by which, as has been stated, the cost of steel has
been reduced at least one-half. Many years elapsed before Mr. Bessemer
succeeded in overcoming all the mechanical difficulties which stood in his
way, and in silencing the opposition which the conservatism of the iron
manufacture offered. Now the process may be said to be not only a success, but a triumph; and its author deserves to be regarded as one of the
greatest benefactors of the human race. For the production of steel,
Mr. Bessemer first proposed to arrest the combustion of the carbon in
the iron so as to leave about one per cent. unconsumed. This point was
found difficult to hit, and he ultimately adopted the method of adding,
after the process was complete, the requisite quantity of carbon in the
form of spiegeleisen, a highly carbonized cast iron. This is the course
now generally adopted; and steel is being thus made in large quantities,
not only in Europe, but in our own country and our own State. A very
complete establishment for the manufacture of Bessemer steel has been
erected by Messrs. Stone, Chisholm & Jones of Cleveland, and there this
interesting and important improvement in iron making may be at any
time seen in successful operation.
The objection has been made to the Bessemer process that it contained
too many elements of uncertainty, that it failed to give constant and
uniform results. This objection has, however, been removed by a very
simple method-suggested by my friend, Dr. Schmidt, and now constantly practiced at the Troy Steel Works-of dipping out and testing a
sample from each five-ton charge, then adding carbon or oxygen as
necessary.
THE SIEMENS-MARTIN PROCESS.
This process, invented and largely employed in France, has lately been
introduced into this country by Messrs. Cooper & Hewitt, at Trenton,
N. J., and has proved here, as abroad, an entire success. It consists in
melting down, in a Siemen's furnace, a quantity of pig iron, then adding
to this sufficient malleable iron to dilute the carbon in the mass to any
desired percentage, and thus produce any required grade of steel. The
point aimed at is reached invariably by testing, from time to time, the
quality of the metal, and adding pig iron or bar iron as required. This
is a simple and perfectly manageable method of producing steel, but it is
doubtful if it can rival in simplicity and cheapness the process of Mr.
Bessemer.