The origins of the telescope - DWC - KNAW

the piece-meal connection of distributed and different bodies of material and
textual, practical and theoretical, mathematical and cultural bodies of knowledge,
packaged and re-packaged when the instrument moved from one place
to another. It is for this reason that the title of this book is not ‘the invention
of the telescope,’ but ‘the origins – plural – of the telescope.’ Moreover, in this
process of circulation not only the instrument that came to be known as ‘the
telescope’ was invented; as Mario Biagioli points out in his contribution to this
volume, Galileo also invented new meanings of ‘invention’ and ‘telescope’ in
the process. Thus, the question of priority – who is the true inventor – is not
only the less interesting question; it is also the wrong question – because in
the sense underlying this question, the telescope itself fails to be invented. It is
worth pointing this out again and again, since the celebrations of the past years
also elicited the all too familiar stories mixing priority claims with national
pride – of which the claim for the Spanish invention of the telescope made
most waves in the media. 11 However, the work of the sixteenth-century Juan
Roget is important, not so much because we would be allowed to attribute the
invention of the telescope to him, but because – as Tom Settle has recently
argued – Roget’s work tells us more about the circulation of the know-how of
lens-making from which the telescope originated. 12
So, which narrative on the origins of the telescope does emerge three decades
after Van Helden’s The Invention of the Telescope? Several chapters in this
book tell us much more on (in Van Helden’s terms of 1977) ‘the prehistory of
the telescope.’ Rolf Willach’s contributions to this volume and elsewhere have
established the degree of progress of the craft of spectacle-making from the
invention of eyeglasses in the thirteenth century. By means of modern optical
measurements on a variety of fifteenth- and sixteenth-century spectacle-lenses,
Willach has demonstrated that only in the early decades of the sixteenth
century – but not before – the craft of lens-grinding had evolved enough to
produce recognizable telescopic images. While Willach claims that the ‘secret’
was in stopping down the objective lens to a small aperture, optical knowledge
steered sixteenth-century mathematicians in exactly the opposite direction.
The contributions of Sven Dupré and Eileen Reeves show that the theoretical
11 Pelling, ‘Who Invented the Telescope?’ (2008). Pelling’s paper was based on two Spanish articles,
published earlier by De Guilleuma, ‘Juan Roget’ (1958) and idem, ‘Juan Roget, Optico Espanol
Inventor del Telescopio’ (1960) See also Pelling’s 2009-web-blog on the topic, in which he has
put some question marks unto the archival accuracy of De Guilleuma, on www.ciphermysteries.com/2009/06/21/the-juan-roget-telescope-inventor-theory-revisited
(consulted on 3 January
2010).
12 Settle, ‘The invention of the telescope. The studies of dr. Josep M. Simon de Guilleuma’ (2009).
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introduction