Following in the same path, the Phoenix Co., of Ruhrort, sent, in 1880, to the Metallurgical Exposition of Dusseldorf, samples of ferro-manganese obtained in a blast furnace, with an extra basic slag in which the silica was almost entirely replaced by alumina. The works of L'Esperance, at Oberhausen, exhibited similar products, quite pure as to sulphur and phosphorus, and they had a double interest at the exhibition, in consideration of the agitation over the Thomas and Gilchrist process (see the discussions which were raised at the meeting of the Iron and Steel Institute). This process unfortunately requires for its prompt success the use of a very large quantity of spiegel or of ferro-manganese, in order to sufficiently carburize and deoxidize the burnt iron, which is the final product of the blowing. The production of ferro-manganese by the blast furnace depends upon the following conditions. 1. A high temperature. 2. On a proper mixture of the iron ores and the manganese. 3. On the production of slag rich in bases. These different conditions may be obtained with but slight variations at the different works, but the condition of a high temperature is one of the most important considerations, not only for the alloys of manganese, but equally as well for the alloys of iron, manganese, silicium, those of chromium, of tungsten, etc. It is also necessary to study the effects produced either in the crucible or in the blast furnace, and to examine the ores which for a long while have been regarded as not reducible. The works of Terre Noire especially made at the same time, in the blast furnace, ferro-silicon with manganese, alloys which are daily becoming more important for the manufacture of steels tempered soft and half soft without blowing. These alloys, rich in silicon, present the peculiarity of being poor in carbon, the amount of this latter element varying with the proportions of manganese. In addition to the alloys used in the iron and steel industry, we shall proceed to relate the recent progress obtained in the metallurgy of other materials (especially copper) by the use of _cupro-manganese_: +---+---------+-------+---------+---------+------+------------------------------ | | Mn. | C. | Si. | S. | P. | | |per cent.| | | | | +---+---------+-------+---------+---------+------+ | A | 18 to 20| 2 to 3| 10 to 12| Traces | |Extra Quality for soft metals. | B | 15 to 18| 3.00 | 10 to 8 | scarcely|About |} Medium Quality | C | 15 to 10| 3.25 | 8 to 6 | percep- |0.100.|} | D | 5 to 10| 3.50 | 4 to 6 | tible. | |Ordinary for hard metals. +---+---------+-------+---------+---------+------+------------------------------