The current consensus among economic historians and historians of technology is that the English patent system before the 1852 reform was very imperfect: would-be patentees were required to endure capricious, erratic, and expensive bureaucratic procedures. Furthermore, inventors found it extremely difficult to exploit their patent rights on the marketplace because of the uncertainties surrounding patent jurisdiction and the lack of sympathy on the part of many judges who regarded patents as unwarranted monopolies. This “consensus view” is the result of two fundamental historical studies of the English patent system carried out during the 1980s: Harry Dutton's The Patent System and Inventive Activities during the Industrial Revolution (1984) and Christine MacLeod's Inventing the Industrial Revolution: The English Patent System, 1660–1800 (1989). Many readers will probably regard Sean Bottomley's study as a root-and-branch attack on what may be called the Dutton-MacLeod “orthodoxy,” making the revisionist claim that the English patent system actually had been functioning in a somewhat effective manner since the middle of the eighteenth century and that, from that date, it did provide inventors with a useful legal device for reaping economic returns from their inventive activities. Perhaps, although Bottomley is very cautious not to make this claim, some hasty readers will even recruit this study to argue that the patent system was actually one of the fundamental institutional prerequisites of the British Industrial Revolution.

Bottomley's book examines the administration of the patent system and the behavior of patents in courts. His reassessment is based on a careful scrutiny of a wide and diversified array of contemporary sources, particularly of legal and administrative nature. It must be noted that the use of the adjective “British” in the title of the book is not at all a misnomer: Bottomley provides a very useful account of the Scottish and of the Irish patent systems, which had been almost completely neglected in the previous literature.

The major point at the core of Bottomley's account is that the English patent system, although originally afflicted by many idiosyncratic and far from straightforward procedures, was actually evolving. Over time, this process of evolution, not characterized by major discontinuities but rather by the cumulative accretion of small changes and adaptations, resulted in a patent system that could be usefully navigated by inventors (with the help of specialized patent agents) in order to obtain and enforce their patent rights. The foundation of this process of adaptive evolution was the introduction of the “specification” requirement in the 1730s. The specification requirement obliged inventors to provide detailed written descriptions of their inventions. Following the introduction of the specification requirement, patents were increasingly assessed and adjudicated on the basis of a set of consistent and “modern” principles according to which patents were in essence regarded as deals in which inventors were granted a temporary exclusive right to the use of their inventions in exchange of the full disclosure of the invention in question to the public. In this way, the introduction of the specification requirement triggered a transformation of the patent system from an “ancient regime” privilege to a property right on intangibles administrated on the basis of relatively modern conceptions.

To support this interpretation, Bottomley provides detailed evidence on the administration and legal functioning of the system, shedding new light, in particular, on the role of specification and of caveats. He is also able to qualify the predominant view about the inaccessibility to the wider public of the technological information contained in the specifications showing that specification and patent abridgments were systematically published on specialist journals of wide circulation. Additionally, Bottomley reassesses the evidence on the adjudication of patent cases, showing that, after the introduction of the specification requirement, trials were increasingly assessed using a relatively dependable set of principles. Concerning the broader economic impact of the patent system, Bottomley's evidence addresses the role played by patents in enhancing the commercialization of new technologies and the role of patents in the foundation of joint-stock companies.

In general, Bottomley's appraisal of the historical evidence is sound and accurate. However, at times, he seems to overlook some pieces of evidence pointing to a less optimistic view of the functioning of the system. In particular, he does not discuss the potential role that class and social prerogatives played for the different actors involved with the patent system. For example, it is well known that Parliament intervened to prolong James Watt's patent for the separate condenser for twenty-five years, but it was less inclined to grant the same treatment to other inventors such as Watt's rival, Jonathan Hornblower. This example suggests that in assessing the role of patent system in this historical phase, one must be alert to the potential role that social and class prerogatives could play for the security of this property right in different contexts.

Furthermore, Bottomley seems to downplay the effectiveness for inventors of “appropriability strategies” that did not rely on patent protection. In this respect, he focuses almost exclusively on secrecy. However, recent research has shown that appropriability strategies based on lead times and reputation could be exploited very effectively by inventors in many industrial sectors (see for example, Ralf Meisenzhal and Joel Mokyr, “The Rate and Direction of Invention in the British Industrial Revolution” in The Rate and Direction of Inventive Activity Revisited, ed. Josh Lerner and Scott Stern, Chicago, 2012; and Alessandro Nuvolari and James Sumner, “Inventors, Patents and Inventive Activity in the English Brewing Industry, 1634–1850,” Business History Review 87, special issue 1 [Spring 2013]: 95–120).

Overall, Bottomley's book should more appropriately be seen as adding many important qualifications, rather than completely overturning Dutton and MacLeod's accounts. In fact, Bottomley's study provides a new appraisal of the English patent system that stands usefully alongside the two “classic” ones of MacLeod and Dutton. I do not think that these three accounts must be necessarily regarded as amounting to completely opposing views, considering that they focus on different pieces of historical evidence. It is indeed possible that soon these appraisals may even be seen in many ways as complementary.