A Note on "Structural Antecedents of the I-Beam"

Abstract

In his study of the evolution of the structural I-shape,1 Robert A. Jewett has called attention to one of the most recurrent and challenging problems in the history of science and technology: the pattern of the relationship between the development of engineering practice and the development of scientific theory. His conclusion supports the widely held view that prior to the middle of the nineteenth century theory contributed little or nothing to the solution of practical problems.2 Although a full analysis of this question, even in the restricted form that Jewett has posed it, would require a massive investigation, I think that on the basis of the evidence he has presented there are grounds for at least a provisional dissent. But, before commenting on that key question, I would like to point out two misstatements and an ambiguity which, although marginal, mar Jewett's meticulous study. He asserts (p. 346) that ancient Greek designers used stone of traditionally rectangular cross-section for their lintels. In fact, however, Greek architects sometimes designed U-shaped lintels reinforced with iron bars! In one arrangement, the iron bar (approximately 3 in. X 4/2 in. X 6 ft.) was set into the top of the lintel which was slightly relieved below the bar to allow it to deflect without loading the stone beam near its center (Fig. 1). In comparison with dressed stone of traditionally rectangular cross-section, this design considerably