The smelting furnace, for smelting the roasted ore into copper-matter, was to consist of a chimney about two feet in diameter, sloping sharply outward for about two feet, and thence sloping gradually inward again for a height of about ten feet. Near the bottom were to be a number of small holes leading from an air passage.
This air passage and the vent for the hot flames from the top of the smelter were to run in parallel pipes made of hollow brick tile, to two chambers containing a checkerwork design of fire-brick. The two pipes were to be interchangeable; so that, when the exhaust had heated one of the checkerwork grids to a red heat, the pipes could be switched, and the incoming air would be warmed by passing through the heated grid. From gnooper hide and wood he could easily construct bellows to pump in the air for the blast.
Molten copper-matte and slag would be separately run off through two separate openings at different levels near the bottom of the blast furnace.
To further refine the matte, he designed a Bessemer converter, that is to say, a barrel-shaped box of layers of fire clay, the inner layer being very rich in quartz sand. This barrel, when filled with molten matte, would be laid on its side; and a hot blast introduced through holes near this side would convert the matte into pure copper in about two hours.
The first converter which he made was rather small, as he expected that it would not last very well without metal reinforcements, and of course he would have no metal for reenforcing purposes until after he had run off at least one heat.
For the extraction of iron, he made crucibles of fireclay, which he set in deep holes in the ground.
On the second morning after the unpleasant homecoming, Quivven appeared. All her rage had burned out, and she was meek and subdued.
With downcast eyes she reported to Myles: “I am ready to go to work now.”
With a welcoming smile he patted her golden-furred shoulder, whereat her old anger started to flare again, but this one remaining ember merely flickered and died out, and she submitted with a shrug of resignation.
So the Radio Man explained to her his plans for the furnaces; then, leaving her in charge of the work, he set out once more to the river of the silver sands, this time accompanied by a heavy guard of Vairking soldiers, and flying a blue flag, as agreed on with Prince Otto of the Roies.