This invention relates to an improvement in the manufacture of large quantities of steel or ingot iron, in regenerative or other reverberatory furnaces, by blowing air into the bath of metal by means of a tuyere apparatus of peculiar construction, capable of being introduced separately into the furnace and into the bath of metal. White or mottled pig-iron is to be used chiefly, but grey pig may be employed also.
Any quantity of steel-scrap or iron-scrap may be mixed with the pig-iron, and this method of working may therefore be also used in the Martin or open-hearth process as now practiced, offering many advantages, because it enables the use of a considerably greater quantity of pig-iron, accelerates the process, increases the production, and makes the product more homogeneous.
On 11 August 1879 WÜRTENBERGER applied for a corresponding patent in Luxembourg under the title of:
Neue Düsenapparatur für Stahlöfen
 DE patent No 10,815 and DE Zusatz Patent No 13,679
 US patent No 238,628
 The corresponding administrative file has not yet been located.
 GB patent 2,243/1879, FR patent No 131,074, Belgium