This same process for the extraction of iron from its natural oxide, without fusion, is practised by the negroes of Fouta-Djallon, in Senegal. After having become acquainted with the elementary process which is practised by the semi-barbarous tribes of the present day, we shall find but little difficulty in understanding all that Morlot, the Swiss naturalist, has said as to the iron-furnaces of pre-historic man, and shall probably agree in his opinions on the subject. Morlot, in his 'Mémoires sur l'Archéologie de la Suisse,' has described the vestiges of the pre-historic furnaces intended for the preparation of iron, which were found by him in Carinthia (Austria). According to M. Morlot, the plan adopted for extracting iron from its oxide in pre-historic times was as follows:--On the side of a slope exposed to the wind, a hole was hollowed out. The bottom of this hole was filled up with a heap of wood, on which was placed a layer of ore. This layer of ore was covered by a second heap of wood; then, taking advantage of a strong breeze rising, which had to perform the functions of the bellows, the lowest pile of wood was kindled at its base. The wood by its combustion was converted into charcoal, and this charcoal, under the influence of heat, soon reduced the iron oxide to a metallic state. When the combustion had come to an end, a few pieces of iron were found among the ashes. By increasing the size of the apparatus used, far more considerable results were of course obtained. In Dalecarlia (Sweden), M. Morlot found smelting-houses, so to speak, in which the original hole, of which we have just been speaking, is surrounded with stones so as to form a sort of circular receptacle. In this rough stone crucible layers of charcoal and iron-ore were placed in succession. After having burnt for some hours, the heap was searched over and the spongy iron was found mixed with the ashes at the bottom of the furnace. The slowness of the operation and the inconsiderable metallic result induced them to increase the size of the stone receptacle. They first gave to it a depth of 7 feet and then of 13 feet, and, at the same time, coated the walls of it with clay. They thus had at their disposal a kind of vast circular crucible, in which they placed successive layers of iron-ore and wood or charcoal. In this altogether elementary arrangement no use was made, as it seems, of the bellows. This amounts to stating that the primitive method of smelting iron was not, as is commonly thought, an adaptation of the _Catalan furnace_. This latter process, which, even in the present time, is made use of in the Pyrenean smelting works, does not date back further than the times of the Roman empire. It is based on the continual action of the bellows; whilst in the pre-historic furnaces this instrument, we will again repeat, was never employed.