Friederich Varnhagen built and operated a blast furnace 100km west of Sao Paulo. Its remnants are still standing, at Ipanema National Forest Park. He wrote notes on his first trials, when he varied air flow, relative quantities of iron ore, fluxes and reductants and evaluated the type of iron produced (gray, white or mottled) and the type of slag. The most surprising experiments he described dealt with the proportions of charcoal and firewood chips to be used. Varnhagen and Eschwege, his former boss, both confessed they knew that only charcoal was used in continental Europe, but they assumed things could be different in Portugal and Brazil. There is no sign of science or clear hypothesis in his reasoning building the experiments and interpreting his results. His conclusion was that “The operation was more regular” when they used 3 parts of chips to one of charcoal.