Ferro e alumínio em Mumford (1934)

But iron has defects almost commensurate with its virtues. In its usual impure state it is subject to fairly rapid oxidation, and until the rustless steel alloys were discovered in the neotechnic period it was necessary to cover iron with at least a film of non-oxidizing mate- [167] rial. Left to itself, iron rusts away: without constant lubrication bearings become jammed and without constant painting the iron ships and bridges and sheds would in the space of a generation become dangerously weakened: unless constant care is assured, the stone viaducts of the Romans, for example, are superior for long-time use. Again: iron is subject to changes in temperature: allowances must be made for expansion and contraction in summer and winter and during different parts of the same day: and without a protective covering of a fire-resistant material, the iron loses its strength so rapidly under heat that the soundest structure would become a mass of warped and twisted metal. But if iron oxidizes too easily, it has at least this compensating attribute: next to aluminum it is the commonest metal on the earth’s crust. Unfortunately, the commonness and cheapness of iron, together with the fact that it was used according to rule-of-thumb prescription long before its properties were scientifically known, fostered a certain crudeness in its utilization: allowing for ignorance by erring on the side of safety, the designers used over-size members in their iron structures which did not sufficiently embrace the esthetic advantages-to say nothing of economic gain-possible through lightness and through the closer adaptation of structure to function. Hence the paradox: between 1775 and 1875 there was technological backwardness in the most advanced part of technology. If iron was cheap and if power was plentiful, why should the engineer waste his talents attempting to use less of either? By any paleotechnic standard, there was no answer to this question. Much of the iron that the period boasted was dead weight. (Mumford 1934:166-7)

MUMFORD, Lewis. 1934. Technique and civilization. New York: Harcourt, Brace and Company.