Review of "The Invention of the Telescope"...

It may seem a little odd to be reviewing a 31-year-old monograph, but stick with it, you'll see where I'm going soon enough...

The whole sequence starts with the review I posted here of Eileen Reeves' brand new "Galileo's Glassworks: The Telescope and the Mirror" (2008, Harvard University Press). Though overall very fascinating, one aspect of this book confused me: why it should be structured in two so radically different (dare I say almost schizophrenic?) halves. You see, while the first 50% covers the amorphous literary pre-history of the telescope, the second 50% deals with the textual minutiae of who told Galileo what and when, and what Galileo probably believed in 1608-9: so the book swings sharply from a super-broad cultural reading to an ultra-close textual reading. An uncomfortable mixture.

Now, the first half particularly intrigued me, so it made sense for me to move on to Reeves' major source for it: Albert van Helden's (1977) brief (but magisterial) "The Invention of the Telescope". If you want your own copy, there are still a couple under £25 available on BookFinder.com (though be quick, the rest are over £50).

Van Helden (for whom Dutch is his first language) had started out by translating Cornelis de Waard's relatively little-known book "De uitvinding der verrekijkers" (The Hague, 1906), which laid out a lot of new evidence on the genesis of the telescope as we know it in the Netherlands: much of the story revolved around the town of Middelburg (which held one of the largest glassworks in Europe), with nearly all key documents written in Dutch.

But de Waard's conclusions - that the telescope had probably been invented in Italy circa 1590, that Raffael Gualterrotti had built such a device in 1598, and that one of which had surfaced in Holland circa 1604, before being replicated by various spectacle-makers and inventors in 1608, leading to an unseemly patent rush - seemed to van Helden not quite to be supported by the evidence. And so he decided to take a fresh look at the documents: and his 1977 monograph was the result.

Having said that, van Helden's final conclusions are practically the same as de Waard's, though not quite as specific: that Giovanbaptista della Porta's claim to have built a telescope (to which his "Magia naturalis libri XX" (Naples, 1589), Book XVII, Chapter 10, p.269 circumspectly alludes) probably does hold up, as does Gualterrotti's claim (perhaps more weakly), though given that the best magnification possible pre-1600 would (argues van Helden) have been only around 2x, the resulting device would have been unspectacular - a telescopic amuse-bouche, rather than the Galilean feast that was to come. And so van Helden concludes that Italians (specifically della Porta) probably did invent the telescope, though they didn't realise it at the time.

Thirty years on, and I think van Helden's monograph stands as a great piece of writing: clear, lean, thoughtful, honest. Best of all, the majority of it (pp.28-64) consists of transcriptions (and English translations) of the important sections of all the relevant documents; so if you don't like his conclusions, feel free to go right to the primary sources (they're pretty much all there), knock yourself out. Perfect.

It should now be clear what I think happened with "Galileo's Glassworks". The elephant in the room (who was not mentioend, but around whom all the furniture was carefully arranged) was van Helden's monograph: this forms a bridge between Reeves' two distinct sections. And so if you add the two books together, you get what amounts to a single coherent work, going from medieval and early modern notions and claims of vision-at-a-distance and burning mirrors (Reeves), through to the myriad claims and counterclaims of the Dutch "inventors" (van Helden), through to Galileo's reception of the new device (Reeves again). At only 231 pages (with endnotes starting on p.167), Reeves' book originally felt to me to be about 60-70 pages short: how curious to find that van Helden's monograph exactly fits the dimensions of that lacuna.

In her acknowledgments, Reeves says that she "benefited most of all... from the intellectual guidance and constant friendship of Albert van Helden, whose own work... is the basis of and inspiration for my own" (p.220). I'd say that while Reeves' book gives context and consequence to van Helden's monograph, reading the former without the latter doesn't really make sense. In fact, I would strongly recommend to Harvard University Press (who publish "Galileo's Glassworks") that they negotiate with the American Philosophical Society to reprint Reeves' book with van Helden's excellent (but scarce) work as an appendix. Now that would be a book truly worthy of the International Year Of The Telescope.

Review of "Galileo's Glassworks"...

Back to the non-fiction grindstone, and next up on my list to read was the very promising-looking "Galileo's Glassworks", by Eileen Reeves: though this has as its main focus the issue of what Galileo knew (and when) about the Dutch telescope, I was told (by Peter Abrahams on HASTRO-L) that it also covers the pre-history of the telescope, which I was more interested in. I was intrigued to see how it would blend these two topics together: it sounded quite ambitious.

And indeed, just as promised, the book turned out to be a game of two very distinct halves. The first half was a kind of wide-roaming literature review of the classical, medieval and early modern texts that promised some kind of proto-telescopes or burning mirrors to their readers: that this was built on broadly the same foundations as Albert van Helden's 1977 monograph "The Invention of the Telescope" is made completely clear in the acknowledgements at the end. Let's be clear: the primary sources for this form a fragmentary, piecemeal soup, whose components interlock and separate eternally - despite all Reeves' hard work, there is no emergent narrative, no thread, no causal proof to be had here. Yet she gives the impression of needing to draw out a story based on the 16th century reception of travellers accounts of the Pharos, in order to give a structural punchline to this section: but unfortunately this never quite hits the spot.

The second half is very much more focused, and reads quite differently: it focuses on the minutiae of correspondence of Galileo and his circle circa 1608-9, as they received (possibly unreliable) reports of mirrors and telescopes coming from France and Holland (often embedded in pro- or anti-Jesuit propaganda), and tried to make up their minds what to make of them - was the new Dutch telescope truly something amazing, or based on the mirror, or was it yet another tall tale?

In the end, Reeves' central point (which hinges on whether Galileo thought the new telescope was built with a mirror or purely with lenses) is well argued, but extremely marginal: and it fails to mesh comfortably with the first half of her text. I came away feeling like I had read two 90-page monographs in quick succession: I desperately wanted her to find a way to knit the two together, to redeem her choice of structure - but this never really happened.

Look: "Galileo's Glassworks" is a lovely, compact, readable book, and pleasantly affordable too (a snip at £14.20 for the hardback). But Reeves can't really reconcile the broad generalities of the pre-history of the telescope with her ultra-close reading of Galileo's "Starry Messenger" and his letters. Ultimately, what's going on is some kind of mismatch in epistemological tone: the first half raises many open-ended issues, while the second half answers a single (quite different) question.

I suspect that somewhere along the way, Reeves lost track of whom she was talking to, and about what: the book ended up being just as much about Sarpi (or even about the ghost of della Porta!) as about Galileo himself, which is surely a sign that her aim drifted off true. Perhaps in the end she simply didn't have enough to say about Galileo in the second half that hadn't been amply said before: which would be a shame, as I would say the first half of her book is really very good, well worth the cover price on its own.

The Digges telescope...

The story of how an Englishman apparently invented the telescope in the mid-sixteenth century is not as well-known as perhaps it ought to be. Its outline was first proposed in 1991 by Colin Ronan, the then president of the British Astronomical Association (and so a credible source): a very readable set of articles (though sadly without matching illustrations) is here, from which I quote below.

Essentially, it boils down to this: that an English Renaissance surveyor and author called Leonard Digges (ca. 1520 - ca. 1559) constructed what was called at the time "perspective glasses" (the term 'telescope' did not appear until the 17th century), quite probably for surveying purposes. However, it seems likely that his son Thomas Digges pointed them to the heavens, several decades prior to Galileo.

From a Voynichological perspective, one of the nice features of the story is that one of our old friends features centrally: when Leonard Digges died, his 13-year old son Thomas was placed under the guardianship of none other than John Dee. Dee, in his preface to Billingsley's 1570 translation of Euclid had this to say:

• 'He may wonderfully helpe him selfe, by Perspective glasses. In which (I trust) our posterity will prove more skillfull and expert, and to greater purposes, than in these days, can (almost) be credited to be possible.'

This, when taken with Thomas Digges' own books and a 1583 report by William Bourne ("an expert in navigation and gunnery"), does all seem to comprise a 'smoking gun' proof that the two Digges in many significant ways predated Galileo by several decades. Which is not, of course, to diminish Galileo's historical importance per se: but rather, to show that the history of inventions is rarely as simple and linear as one might think.

One last thing: in the Netherlands patent uproar over the first 'official' telescopes, "the son of Sacharias Jansen [a better Wikipedia page is here], another of the claimants, later stated that his father [Hans Jannsen, the probable inventor of the microscope in 1590] already had a telescope of Italian manufacture, dated 1590". So the full story behind the invention of the telescope most likely remains obscure and tangled...