Eileen Reeves, Galileo’s Glassworks: the Telescope and the Mirror

Eileen Reeves, Galileo’s Glassworks: The Telescope and the Mirror (Cambridge, Mass: Harvard University Press, 2008). 240 pp. $23.00 Hb. ISBN 978-0-6740-2667-4

In Galileo’s Glassworks, Eileen Reeves deftly reassesses the lapse between the invention of the telescope in Middleburg, September 1608 and the publication of Galileo’s Sidereus Nuncius (Starry Messenger) in Venice, March 1610. Mapping out the cultural, scientific and technological developments during this intense period of optical innovation, Reeves investigates Galileo’s knowledge of, and contact with, this groundbreaking invention. The central question she proposes is, ‘Why did Galileo pretend not to hear the news [of the telescope] for so long?’ (8). Employing her acute skill in translation, Reeves ploughs through an impressive collection of manuscripts and letters, to bring forth a lucid, scholarly discussion between the different intellectual circles from across Europe. In doing so, she references a striking range of literary and cultural sources, including Ovid, Guillaume de Lorris, Geoffrey Chaucer, Roger Bacon, Thomas Digges, Edmund Spenser and Giovanni della Porta.

The first chapter discusses the role of the imperial mirror, which sets the backdrop for the invention of the telescope. Telescopic vision, Reeves argues, predates the telescope. Citing from as far back as the 9th century to the Pharos of Alexandria, Reeves convincingly illustrates how mirrors were employed as a method of defence and instruments to spy with. The imperial mirror, she explains, was used to make the enemy visible. This fascination with seeing into the invisible, leads Reeves to her second chapter, ‘Idle Inventions’. Shifting from military to domestic use of the mirror, Reeves discussed how the designs of metal and glass mirrors were used to see ‘near and far’ (49). Most importantly, she argues the significance of the camera obscura and della Porta’s combination of mirror and lens, as key to the invention of the Dutch telescope (made of two simple lenses, one convex and one concave). What is refreshing about Reeves’ approach is her use of comparative literature, which is elegantly woven into her argument, adding a rich historical texture to the narrative. Appropriating Spenser’s ‘world of glass’ from The Faerie Queen, Reeves describes the months leading up to the Dutch telescope as a time of ‘catoptric wonders’ (45).

In the chapters that follow, Reeves cogently revises the chronology of Galileo’s life around the invention of the Dutch telescope. Chapter Three, however, focuses more on Galileo’s close associate, Paolo Sarpi, than Galileo himself. Most interestingly, Reeves holds Sarpi (rather than Francesco Maurolico or Johannes Kepler) as ‘a representative figure’ (82) of optics in northern Italy around 1600. In her detailed comparison between Sarpi and della Porta, Reeves outlines the use of concave and convex mirrors and lenses, as well as shadow squares, to demonstrate how far catoptrics had come along since the ‘cerbottana’ (a long tube used to see afar). Tellingly, Galileo’s fascination with the parabolic concave mirror and his invention of the military compass used to find the height of distant objects are brought to our attention. Through deft arrangement of their correspondence, Reeves goes on to speculate convincingly on the possibility that Sarpi, della Porta and Galileo might have discussed optical devices when meeting in Padua in 1593. The speculative element of Reeves’ reading simultaneously adds to and weakens her analysis. On the one hand, it allows the reader to imagine how these key figures may have gathered, on the other, it seems to fictionalise the events in favour of her argument.

In the fourth chapter Reeves introduces the ‘French mirror’, an optical device owned by the French King Henry IV’s confessor, Father Pierre, which allowed one ‘to see playnly whatsoever his Maiestie desired to know’ (117). Reeves argues how the French mirror played an important role in Sarpi and Galileo’s erroneous impression of the refracting telescope. Using Jacques Badovere as a connection between Father Pierre and Galileo, Reeves insists that it is ‘feasible that Badovere had some notion of Galileo’s study of optics’ (128). In doing so, she concludes that Sarpi and Galileo ‘must have known about the existence of the Dutch invention by November 1608’ (128). As we journey from antiquity to 1608, Reeves highlights numerous facets of the invention. One facet, however, makes its presence felt mostly by its absence: the role of Galileo himself. Rather than Galileo, Galileo’s Glassworks is dominated by Galileo’s contemporaries and associates (such as Sarpi and Badovere) – it is Badovere, not Galileo, whom Reeves titles as the ‘credible messenger for technological developments’ (144). Thus, if the reader is looking for an in-depth account of Galileo’s works on the telescope or on Jupiter’s satellites they should turn elsewhere. Galileo’s Glassworks is predominately concerned with the culture of optics in which Galileo was a member.

Galileo’s Glassworks offers a comprehensive and learned study of the events surrounding the invention of the telescope in 1608. Whilst the bibliography and index make it easy to locate sources (impressively translated by Reeves herself) and the illustrations illuminate how the two lens-and-mirror combinations for the Dutch telescope work, the book would greatly benefit from a timeline to set the chronology of the events prior to and after the invention. Overall, Reeves paints a rich and dense landscape of optical science onto which she projects Galileo. Shedding light on the less renowned figures of scientific discovery, this innovative book is a valuable contribution to the field of optics and history of science.

Shani Bans, University College London