Page:Popular Science Monthly Volume 40.djvu/64

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54
THE POPULAR SCIENCE MONTHLY.

the tips of these are incased in a clay tube. Wooden sticks are fastened to the middle of the bladder covers or to the upper end of the skins. By working these handles up and down air is forced through the pipes into the tube and through the fire. This is built in a hole dug in the ground. The heated iron is worked hot between two stones used as anvil and hammer. Assegai-blades are made with this poor outfit of such excellence that they may be sharpened so as to be used as razors, and so pliable that they may be bent double and then straightened after reheating. This is iron working, not smelting. Schweinfurth describes how the Dyoor get the iron from the ore, and the process is practically the same throughout Africa, In March, just before seeding-time, he says, they go to the woods to smelt iron. In the shaded center of a very wooded spot they make groups of furnaces of clay. These are cones not more than four feet high, widening to a goblet shape. A cup-shaped cavity at the top communicates by a small throat with the main cavity of the furnace, which is filled

Fig. 11.—African Smiths at Work.

with charcoal. The upper receiver is filled with fragments of ore about a cubic inch in size. The hollow tunnel extends lower than the ground-level, and the melted ore, finding its way down through the fire, collects below. Openings here admit air and allow the withdrawal of slag. The iron has to be twice heated, and when taken out is in small bits which on reheating are beaten into one mass.

Metal-working had doubtless an exceedingly slow development; but it is remarkable how some people, strangers to the art as originators, acquire it as imitators. Thus the Sacs and Foxes