Engineering Theory in the Making: Aerodynamic Calculation "Breaks the Sound Barrier"

Abstract

controls of the Bell XS-1 experimental aircraft, became the first person to fly faster than the speed of sound. Aerodynamic design of this straight-wing monoplane was based on wind-tunnel tests of a model plus empirical knowledge, still embryonic, of airflow near sonic speed. Engineering theory, by contrast, took another five to six years to break the sound barrier by calculations for even a simple aerodynamic shape. The theoretical problem thus had its initial solution after the practical one, a common situation in engineering. The story of the XS-1 has been told many times. This is the story of the theoretical breakthrough. The making of engineering theory receives little detailed attention in the historical literature. Events and key players in this form of engineering science have been written about, but few fine-grained case studies exist of how a theory came into being.' This is in a sense curious, since history of technology has been focused largely on artifacts, and an engineering theory is itself an artifact-more specifically, a tool-to be employed in designing other artifacts. Theoretical