however, will have observed that, even with every precaution in the
blast furnace practice, pig iron will often be obtained with so high a
percentage of sulphur as to render it useless for the Bessemer acid or
basic processes. If the desulphurization in the blast furnace is
carried sufficiently far, it is always necessary to work the furnace
hot, and thus to obtain hotter iron than is desirable for further
treatment in the converter. On the other hand, the method of further
desulphurization outside the blast furnace, described in this paper,
presents the double advantage that part of the blast furnace can be
kept cooler, and thus lime and coke be saved, and that there is a
certainty that no red-short charges are obtained in the treatment in
the converter, while the pig iron passes to the converter at a
suitable temperature.

[Illustration: FIGS. 1 through 5]

A further advantage presented by the direct process described in this
paper is that the Bessemer works is independent of the time at which
the individual blast furnaces are tapped, as the pig iron required for
the Bessemer process can be taken at any moment from the
desulphurizing plant. In Hoerde, where the mixing and desulphurizing
process has for a considerable time been regularly in use, it has been
found that all the chief difficulties formerly encountered in the
method of taking the fluid pig iron direct from the various blast
furnaces to the converter have been obviated. At Hoerde the mixing and
desulphurizing plant shown in the accompanying engravings is employed.
This apparatus holds 70 tons of pig iron. It is, however, advisable to
have an apparatus of greater capacity, say 120 tons. The apparatus has
the shape of a converter, and the hydraulic machinery by which it is
moved is simple and effective. An hydraulic pressure of eight