h the hand from the impurities which soiled their surface. then coal and ore were arranged in heaps and in successive layers， as the charcoal-burner does with the wood which he wishes to carbonize. in this way， under the influence of the air projected by the blowing-machine， the coal would be transformed into carbonic acid， then into oxide of carbon， its use being to reduce the oxide of iron， that is to say， to rid it of the oxygen.
thus the engineer proceeded. the bellows of sealskin， furnished at its extremity with a nozzle of clay， which had been previously fabricated in the pottery kiln， was established near the heap of ore. using the mechan
第66章知识(18/23)