Technological Knowledge without Science: The Innovation of Flush Riveting in American Airplanes, ca. 1930-ca. 1950

airplanes had rivets flush with the surface. To observers outside the airplane industry this change, if they noticed it at all, must have seemed straightforward and even trivial. In fact, since flush riveting had never before been used in plates as thin as those in aircraft, a great deal of learning was necessary. We may therefore ask, Why and how did the change to flush riveting take place? And what knowledge did the learning process generate that was not available before? In earlier papers I have explored two examples of technological knowledge close to the interface between engineering and science, one concerned with experiment and one with theory.' My purpose here is to move to the other end of the spectrum and take up a case far