She applied the “Page 99 Test” to her new book, Making Jet Engines in World War II: Britain, Germany, and the United States, and reported the following:
Page 99 is part of my case study of the work done by de Havillands on the Goblin jet engine. Rather than focusing on the titular inventor, it, like the book, emphasizes the other people who worked on early jet engines and the way in which knowledge and resources transferred from a pre-existing technology (piston aircraft engines) to the new engines.Learn more about Making Jet Engines in World War II at the University of Chicago Press website.
Throughout, the book connects deep technical design decisions and ideas to the previous knowledge of the designer (how the old was the scaffold for the new), in this case Frank Halford, and to institutional concerns (Halford’s company changed from a consulting bureau to a part of an aero-engine company during the war). Here we see in detail how the temperaments and experience of different individuals corresponded to different engineering decisions. Far from understanding invention as the act of an independent individual, we see that invention is influenced by the organizations where it occurs.
This page illustrates well how developing a jet engine fit in with the institutional goals of the existing aero-engine industry. Although rarely mentioned, all of the early jet engines that were used by military air forces (the first in 1944 in Britain and Germany) were produced by existing aero-engine companies, each of which had existing wells of expertise and resources.
Making Jet Engines in World War II uses the case of making jet engines to offer a different way of understanding technological innovation, one that reveals the complicated mix of factors that go into any decision to pursue an innovative, and therefore risky technology. The book shows how the approaches of different nations to the jet engine differed because of each country’s war aims and industrial expertise. Germany, which produced more jet engines than any other nation, did so largely as replacements for more expensive piston engines. Britain, on the other hand, produced relatively few engines—but, by shifting emphasis to design rather than production, found itself at war's end holding an unrivaled range of designs. The US emphasis on development, meanwhile, built an institutional basis for postwar production.
Technology is shaped by many things; it is up to us to recover them if we want to understand the decisions that still shape our world today.