The operation of carbonizing woolen rags for the purpose of obtaining
pure wool, through the destruction of the vegetable substances contained
in the raw material, maybe divided into two parts, viz., the immersion
of the rags in acid, with subsequent washing and drying, and the
carbonization properly so called. The first part is so well known, and
is so simple in its details and apparatus, that it is useless to dwell
upon it in this place. But the second requires more scientific
arrangements than those that seem to be generally adopted, and, as
carbonization is now tending to constitute a special industry, we think
it is of interest to give here a typical plan for a plant of this kind.
It will be remarked that this plan contains all the parts in duplicate.
The object of this arrangement is to permit of a greater production, by
rendering the operation continuous through half of the apparatus being
in operation while the other half is being emptied and filled.

Figs. 4 and 5 give plans of the ground floor and first story, and Figs.
1, 2, and 3 give vertical sections. The second story is arranged like
the first, and serves as a drier. As we have said, there is a double
series of chambers for carbonization, drying, and work generally. These
two series are arranged on each side of a central portion, which
contains the heating and ventilating apparatus and a stone stairway
giving access to the upper stories. The heating apparatus is a hot air
stove provided with a system of piping. The rags to be carbonized or the
wool to be dried are placed upon wire cloth frames.

The carbonization is effected in the following way: When the heating
apparatus has been fired up, and has been operating for about half an
hour, the apertures, i, are opened so as to let the air in, as are also