In 1937, the German Otto von Ohain ran a jet engine he designed and later that year British Frank Whittle did the same. The British government, however, did not capitalize on Whittle's genius, and so Germany came to outproduce Britain in jet fighters during the Second World War. The United States, meanwhile, failed to produce their own jet engines and had to purchase British designs. With such a well-established story, it is not immediately clear why anyone should delve again into this familiar moment of aviation history. But, as Making Jet Engines in World War II convincingly shows, our blindness to the problems that beset our histories of the jet engine exposes much larger faults that run deep within how scholars think about technical change in the twentieth century.

Central to studies of innovation in the twentieth century is a story about the replacement of the independent inventors of the nineteenth century with the industrial research laboratories of the twentieth. This ‘transition narrative’ was in the textbooks in the 1970s and has remained there since. But, Giffard argues, the story is misleading. It suggests the design of a new machine as the endpoint in the process of innovation and so skips everything in between the drawing board and the use of a novelty. Within this space, the unappreciated creativity of industry appears: the laboratory and the lone inventors move away from the centre of the story while the processes of development and production are written into it.

The structure of Giffard's book reflects this important conceptual reorientation. Giffard discusses the production of the jet engine first, then its development, and finally its invention. For it was the production needs of each country that defined the aeroplanes that were made. Following this point through radically changes how we understand the creation of jet engines during the Second World War. Contrary to the familiar story, we find that Britain poured a great number of resources into developing jet engines, but concluded that they would be of little use in wartime and so refocused on building powerful and reliable jet engines that could form the basis of a strong post-war industry. Germany may have produced eight times as many jet engines as Britain in the Second World War, but not due to technical might. The Nazis were short on the strategic metals needed to develop piston-powered aeroplanes, but had masses of labour. Thousands of slave labourers in underground factories were central to the manufacture of German jet engines, which were designed so that they could be built by unskilled workers. Performance was sacrificed for production need. German jet engines were so unreliable that they were useless in combat. The decision of the United States to purchase a British-designed jet engine was not a sign of failure, but a shrewd move that ensured the Americans could develop a jet engine industry as quickly as possible. Even more than the British, the Americans came to focus on the long-term strength of their jet engine industry, not on an imagined wartime need. The American strategy worked. Not long into the post-war years, the United States came to challenge British superiority in jet engines.

Giffard shows how the jet engine was largely developed within the aero-engine industry, whose pre-existing engineering culture, machines and methods were crucial in transforming jet engines from designs into aeroplanes. One of the most transformative companies was the British firm Rolls Royce, whose work in jet engine development Giffard details for the first time. Rolls Royce identified the turbojet as key to its future and dedicated huge internal resources to the new engines, as well as taking advantage of the knowledge of other firms, the resources of the government, and their pre-existing expertise. But continuities of knowledge could also hamper the development of the jet engine. Sometimes firms held out a commitment to awkward jet engine designs because of a prior experience with certain elements of it. Different areas of industrial knowledge also mattered. Steam turbine companies were almost universally unsuccessful in developing jet engines as they found aeroplanes vastly different from the design of heavy, immovable plant. For better or for worse, the old shaped the new in jet engine development.

In talking about invention, Giffard broadens the traditional focus on Whittle and von Ohain to look at Power Jets and the Ernest Heinkel Aircraft Company, the institutions where these figures worked. For more than five years, Whittle had much control over Power Jets. But ultimately it alienated the government and the aero-engine industry by pursuing designs that served little market or military need. In stark contrast to Whittle, von Ohain had little influence over executive decisions in his firm. Against his wishes and for several years, the Ernest Heinkel Aircraft Company focused on building stunt engines to attract funding, rather than making jet engines for military use. Neither Whittle nor von Ohain got their jet engine designs into production. Stories of their importance to the creation of the jet engine were constructed, in part, for political reasons. In post-war Britain, Whittle was consciously turned into the singular inventor of the jet engine by a country relishing its own technological brilliance and by politicians who thought championing him would bring export orders. Von Ohain was brought into a dual-inventor story as Germany sought to normalize its aviation industry and rid it of its Nazi past. Both narratives gain much of their potency from the wider cultural significance of stories about heroic, lone inventors.

Historians should not adopt popular judgements of what innovation is and where it takes place. Such assumptions, as Giffard points out, have produced a great loss of understanding that we can no longer countenance. The first step in building a far richer history of technical change is for all historians interested in invention to look at this book. Perhaps then we will see some more novelty in our histories of innovation.