Jesse Ramsden was a superb instrument maker—one of a kind, unmatched in England and continental Europe in the late eighteenth century. For instance, when the director of the Paris Observatory, Jean-Dominique Cassini (Cassini IV), visited Ramsden's workshop in 1787 to order a large transit, he was surprised by Ramsden's extensive knowledge in all matters of instrument making as well as in geometry, astronomy, mechanics, optics, and physics. After two or three conversations with the London virtuoso, Cassini “became discouraged to realise that we would never have such a consummate artist in France. … This man is an electrical machine which has only to be touched to emit sparks” (142).

Everyone who commissioned an instrument from Ramsden knew he had no equal. All knew, however, that they would also have to be extremely patient with him, because repeated delays were Ramsden's second most famous hallmark: “That wretched Ramsden is really making me wait for the circle which he promised me so many years ago” (113). One considered Ramsden an “arch-liar,” while another thought him “sluggish in the making of instruments” (77). Thomas Hornsby, Savilian professor and astronomer at the Radcliffe Observatory near Oxford, penned his frustration to the Duke of Marlborough: “Is there no news from the sieur Ramsden? I believe I must go and beat up his quarters myself ” (77).

This “love/hate” relationship with Ramsden is recurrent throughout the book. It exhibits well the pride and anxieties in ordering an instrument designed and made by such an obsessive perfectionist. Interestingly, the real protagonists in Anita McConnell's story are the instruments—the dividing engine, astronomical circle, geodetic theodolite, transit, sextant, balance, and much more—rather than Ramsden himself. Owing to a lack of sources—there is a complete absence of personal or business papers on Ramsden and his successor, Matthew Berge—a standard biography of Ramsden is impossible. McConnell's great strength in this book is having been able to reconstruct Ramsden's prominent career mostly through the scientific instruments he made and from those who commissioned them. McConnell's scholarship is remarkable. She masters the technical details of these complex machines as well as the wealth of contemporary sources and correspondences she unearthed dealing with Ramsden's life and business.

The book is roughly chronological, starting with Ramsden's early years in London's Haymarket and his close relationship with the Dollonds, a family of famous opticians. (Ramsden married the youngest daughter of John Dollond in 1766.) In 1773 Ramsden moved to 199 (and later added 196) Piccadilly, adjacent to St. James's churchyard, the home and workshop where he stayed the rest of his life. In chapter 3 we learn about Ramsden's pivotal instrument, the dividing engine, that made him the successful instrument maker he soon became. This machine was designed and used to accurately engrave the circular graduated scales on small measuring instruments—especially sextants, of which Ramsden and his assistants made around 1,450 between 1760 and 1800. The larger instruments of more than two feet in radius, such as the great astronomical circles found in observatories, were still engraved by hand. To help him, Ramsden enrolled an army of assistants that reached between forty and fifty individuals, something highly unusual even for the second half of the eighteenth century. Chapter 4 describes life in Ramsden's workshop—the strict rules and regulations, salaries, tools and materials—and the specialized workforce (apprentices, journeymen, and simple workmen) hired from the British Isles as well as from the Continent. This chapter is unquestionably the most useful to the broader community of preindustrial economic and social scholars.

The next two chapters focus chiefly on the special commissions received by Ramsden to furnish European astronomical observatories. (Also briefly mentioned are the instruments embarked on scientific expeditions—including captains James Cook’s, Jean-François Galaup de Lapérouse’s, and George Vancouver’s). The dividing line chosen by McConnell is 1786, the year Ramsden was elected a member of the Royal Society. Each section gives the history of an observatory, the instruments ordered, and the (often difficult) dealings with Ramsden. Some famous observatories (Paris, Palermo, Dunsink, Brera, Greenwich) as well as private ones are described in various degrees of detail. Chapters 7–9 offer next short accounts of an assorted set of instruments—thermometer, barometer, micrometer, microtome, precision balance—made in Ramsden's workshop. In particular, we learn about Ramsden's great geodetic theodolite, which was used to measure with great precision degrees of longitude for cartographic purposes. Thanks to the harsh accusations made against this instrument by General William Roy, who was in charge of the Paris-Greenwich triangulation on the English side, we are in possession of precious documents describing Ramsden's design and construction of this important machine. The last part of the book deals with Ramsden's final years and his successor, Matthew Berge.

The book has a strong scholarship and is a must-read reference to Ramsden and his time, one I will often go back to. Yet I did not enjoy reading it. The overall prose is somewhat ungraceful, episodic, and telegraphic. Part of the text appears pieced together as if the author did not really know where or how to properly introduce certain individuals and institutions. The short interludes on J. H. Magellan, Gianntonio Rizzi Zannoni, Samuel Réhé (or Rhee), and the Specola Caetani are specific examples. In a few cases the descriptions of events start at one place in the book and are fully concluded later (e.g., the Dunsink Observatory, 113–17 and 257–58). Some insights are fascinating, such as how weather affects the production of instruments, while the few accounts of political events are mostly irrelevant. It is not a book I would recommend reading in its entirety. Nevertheless it is an important contribution to the specialized field of scientific instruments. By carefully picking the relevant chapters and sections, this book also expands our understanding of the rise of scientific entrepreneurship in preindustrial Europe.