Review of “The Long Route to the Invention of the Telescope”…

by ⋅ 1 Comment

Equal parts brilliant and frustrating, Rolf Willach’s “The Long Route to the Invention of the Telescope” (2008), which reprises his featured sessions at the September 2008 conference in Middelburg, is a book formed of two stunningly different halves.

Through his insightful and breathtakingly meticulous analysis in the first seven chapters, Willach dramatically reconstructs the history of optical craft in the centuries preceding the invention of the telescope. Simply put, by casting the development of optics in terms of the technological and craft-based elements in making glass objects, he has produced without any doubt the most important new writing on the subject in decades. However, in chapters eight to eleven, his obvious eagerness to build on his main findings to retell the history of the telescope leads him to make what seem to me to be terribly, terribly weak inferences. Yet if that were to cause historians to look askance at his whole work, it would be a terrible shame, for there is a huge amount to be proud of here.

Willach is an independent scholar with his very own tightly-focused research programme: applying quantitative scientific testing methodologies to old lens-like objects to try to understand the ways in which they were made. Over many years in dogged pursuit of this quest, he has examined the Nimrud Lens, the Lothar crystal, lapides ad legendum (reading stones) embedded in liturgical art, curved glass covers in reliquaries, spectacle lenses embedded in a bookcase, rivet spectacles found beneath a nuns’ choir, spectacles in private collections, early telescope lenses etc. Furthermore, there seems to be no end to the range of physical and optical tests he has at his disposal: and he has even built and used his own a replica lens grinding machine. He has also delved deeply into the practical chemistry, physics and craft of glassmaking and glassblowing. In short, in a world where many self-professed experts are content to simply talk a good talk, it is wonderfully refreshing to find someone who has really, really walked the walk.

For Willach, the physical evidence strongly indicates that spectacle lenses developed not out of reading stones (pieces of rock crystal hand-turned on a wheel but progressively more curved towards the edges), but from the large number of reliquary covers needed to accommodate the tidal wave of martyrs’ relics that washed back into Europe after the Crusades. Just as with the reading stones, these were formed from pieces of rock crystal, and individually ground and polished on some kind of wheel, just as similar items had been turned since antiquity.

At some stage, glass began (quite understandably) to replace the far more expensive rock crystal. But when? Willach translates (pp.33-37) “cristallum” in the 1284 Venetian trade regulations as if it referred to the innovative Murano cristallo glass invented in the mid-Quattrocento by Angelo Barovier (and which is first documented in the context of a salt cellar in 24th May 1453, according to Gianfranco Toso’s “Murano: A history of glass”, p.46). Here, Willach has got the technological sequence right, but the timeline plain wrong. And so it seems highly likely to me that early glass spectacles were tinted or coloured (as indeed all other glass-made items were at that time), until 1450 at the earliest.

The first mass-manufactured glass lenses were made in a devastatingly simple way: by blowing a pear-shaped bubble of glass (contrary to popular myth, these bubbles were never spherical), stamping out circular blanks from it, and then subsequently grinding down the concave side of the blanks until flat. Used up until around 1500, this approach produced plano-convex lenses with a distinctive unground curved side and a ground flat side – though occasionally reasonably good near the centre, they were simply not optically good enough to be used in telescopes.

The next technological change came from Nuremburg, where from around 1478 a small group of spectacle-makers began to produce plano-convex lenses using moulds. For a while, these were ground only on the curved side with the planar side left unground: but it was only about 1500-1510 when both sides began to be ground that the quality of these lenses leapt ahead. This was arguably the first point when telescopes began to become optically possible (but not initially in Italy, for the Nuremberg spectacle-makers managed to keep their secret intact for a long time).

Yet the hunger of the European mass-market for cheap spectacles meant that, before very long, the quality of mould-made lenses began to go downhill. Ultimately, lens moulds ended up (as Girolamo Sirtori lamented in 1612) simply being hammered roughly into shape rather than measured against a perfect curve. By 1600 or so, all the subtle craft skills required for making good lenses had (apparently) long been forgotten.

All of which forms the moving technological and craft canvas upon which the history of optical devices (such as telescopes, microscopes, and camera obscuras) was painted: and, thanks to Willach’s sustained efforts, it is now very much better-defined than it has ever been. But… what of the telescope, then?

As far as the prehistory of the telescope itself goes, there used to be one big open question: despite the fact that convex and concave glasses were produced in large quantity from around 1450, why was the telescope not invented until circa 1600? I think it is a measure of Willach’s massive redefinition of the entire field of study that this now seems hugely simplistic, if not actually naïve. Yet this is essentially the question that he sets out to answer in his final chapters.

As an example: the writing of Girolamo Fracastoro has long been a curious anomaly in the telescope’s prehistory: in 1538, Fracastoro unambiguously described a twin lens telescopic arrangement – but this apparently was not picked up by anybody. Yet within the framework of optical history as rendered by Willach, I think we can get a glimpse of the reason why that should have been the case: in Fracastoro’s time, the craft of lens making was on the way down – that is, Fracastoro just happened to be living in the brief period early in the 16th century when moulded lenses were still made with a bit of craft in Venice – there was (I conjecture) only a brief window around that time when off-the-shelf lenses would have been good enough to be used in a telescope.

But why is Willach so certain that things had recovered by 1608? If, as Girolamo Sirtori wrote in 1612 (which Willach approvingly quotes), the craft of spectacle-making had indeed been lost, from where did the craft of telescopes emerge? As I wrote in my September 2008 History Today article, the notion that three Dutchmen all dreamt the same hi-tech dream at the same time (and then went away and executed it independently of each other) is extraordinarily suspect – and, I would now add, the kind of mass-produced, low-quality glass spectacle market that seems to have been in existence circa 1600 makes this even more unlikely.

But all of this begs a large question about one of Willach’s assumptions. Albert van Helden  baldly expresses the assumption in his introduction to Willach’s book, when he notes that the telescope’s “origins clearly lie in eyeglasses”. I would say that, actually, the first half of Willach’s book does an excellent job in undermining that basic presumption: and that we are now at the point where we can start to glimpse what was really going on – and I now believe it wasn’t anything to do with eyeglasses.

There was a quite different class of glass-made lens-based optical artefact made at the time, which (thanks to David Hockney) has recently received a significant amount of academic attention and debate (particularly in “Inside the Camera Obscura – Optics and Art under the Spell of the Projected Image“, edited by Wolfgang Lefevre) – the camera obscura. The connection between this and the telescope is a big story yet to be properly grasped and retold: but one strand I would like to flag straightaway comes from Sven Dupré’s fascinating article (in Lefevre’s book), “Playing with Images in a Dark Room: Kepler’s Ludi Inside the Camera Obscura“.

Kepler mentioned in his 1604 book Paralipomena “an experimentum […] which I saw at Dresden in the elector’s theater of artifices […] A disk thicker in the middle, or a crystalline lens, a foot in diameter, was standing at the entrance of a closed chamber against a little window, which was the only thing that was open, slanted a little to the right. […] But the walls were also particularly conspicuous through the lens, because they were in deep darkness.” But hold on a moment… who made this camera obscura lens, so obviously predating the Dutch telescope? Perhaps it is to letters in a Dresden-linked archive that telescope historians should now be looking…

Of course, it would be a curious irony if Willach’s scintillating research actually had the effect of severing his presumed link between spectacles and telescopes. And my conclusion (that this is so) will doubtless be no more than one voice amongst many in the field. Regardless: whatever your own angle, I strongly urge you to buy a copy of Willach’s excellent book and make up your own mind. This truly is history in the making – exciting times.

Review of “Bearing the Heavens”…

by ⋅ 1 Comment

I’ve just come back from 24 hours in Swansea, a town where, bizarrely, almost every road is one way (usually the opposite way to which you want to go). At the top of Mount Pleasant, students eke out their existence, one drunken stumble away from a 5-minute death-roll down Constitution Hill’s 45 degree gradient. Swansea is the kind of place where (ideally) you’d like a hang-glider to get to town, a satnav implant to get around, and a cable-car to get home again. But still, the beer’s good, so I can forgive all that… 😉

All of which springs to mind simply because I’ve just read a book on Tycho Brahe by Adam Mosley, history lecturer at the University of Swansea. From his office, most of the bright lights in the evening sky are doubtless not stars or planets, but roomlights in digs at the top of the hill, full of students massaging their aching quads and calves, & wondering why their 50cc scooter’s clutch burnt out in only two days.

In many ways, Mosley’s book – “Bearing The Heavens: Tycho Brahe and the Astronomical Community of the Late Sixteenth Century” (2007), Cambridge University Press, ISBN13: 9780521838665, £55.00, US$105.00 – dovetails quite neatly with “On Tycho’s Island”, as reviewed here recently: whereas the latter looks inwards at Brahe’s insular life on Hven, the former instead looks outwards to Brahe’s links with the external world. To do this, Mosley focuses on three things – Brahe’s letters, his books, and his instruments.

The writing is brisk and accessible throughout (though I felt devoting the first chapter to a justification of why he chose the punning title “Bearing the Heavens” was somewhat superfluous), and the two big chapters on books and instruments cover the ground well. But I have to say that this is all a bit of a feint, a distraction from Mosley’s actual thesis – which is concerned solely with the importance to the history of science of Brahe’s letters in their context. This is the real deal, the stuff that you can tell he’s excited about here.

And, I think, rightly so – Mosley’s book essentially sends out a ‘call to adventure’ to historians of Renaissance science, that they have woefully undervalued the usefulness of letters. Book publishing is just the tip of the iceberg of ideas – even these days, printing your own books is no walk in the park (trust me, I’ve tried it), and the difficulties involved 400-500 years ago were far greater, even for driven people of significant means such as Brahe. Renaissance letters were often copied and circulated, or even collated for later publication: and so Mosely argues that it is the huge interconnected web of letters that form the underwater bulk – and it is to this largely unseen mountain we should be devoting our attention.

Regular readers of this blog will know that this is a zeitgeisty angle (though perhaps still falling just short of being trendy), exemplified by (for example) Josef Smolka’s ongoing study of Tadeas Hajek’s letters to/from Andreas Dudith. What separates Mosley’s exposition is that he simply does not accept that it is a marginal area for study – for him, correspondence is king, and should occupy centre stage for our understanding of science pre-1600.

For a while, I’ve been thinking along these lines: I even tried creating a database in Freebase to try to map out & visualize the connections between various 16th century letter-writers, to try to glimpse the “invisible colleges” as they formed, flourished and faded. Yet when I saw Mosley’s Figure 2.1 on page 36 (which tries to do this for Brahe’s immediate network), I suddenly realised the staggering enormity of the challenge and gave up on the spot.

Fig 2.1 from Adam Mosley\'s \

Ultimately, what historians of science would need is a gigantic collaborative correspondence database, that could be used as a cross-archive finding aid. Even though a few people’s letters have been studied in depth (such as Christopher Clavius, Tycho Brahe, Athanasius Kircher, etc), libraries and archives (particularly private archives) must still have an enormous collection of pearls of which historians are unaware.

Perhaps others have already advanced Mosley’s thesis just as eloquently and persuasively: but it is an idea whose time (I believe) has now come. Will others heed his call? I hope so…

Review of “On Tycho’s Island”…

by ⋅ 3 Comments

People don’t generally know a lot about Tycho Brahe, which is a shame. In most accounts of the history of astronomy, his bright star tends to get eclipsed by the twin 17th century supernovae of Kepler and Galileo. But scratch the surface of the story, and it’s really not that simple…

Brahe was a Danish nobleman with a singleminded desire – to understand why the motions of the planets in the heavens failed to match what the best astronomical tables (based both on Ptolemaic and Copernican systems) predicted. Somehow, he engineered an arrangement by which King Frederick II granted him the island of Hven to pursue his astronomical studies for the glory of Denmark: yet what Brahe set up there was as much a social institution (like a postgraduate research community) as a technical observatory – to get the job done, he needed people just as much as equipment.

In fact, Tycho tried to get all the brightest young astronomers of the time to work on his island (for peanuts, it has to be said, but that’s research for you), and to correspond with everyone who was anyone in astronomy. Even so, things didn’t always work out as planned, most notably with Ursus (though I believe the question of whether Ursus was as big a scoundrel and weasel as Brahe tried to make out is far more open than most historians credit).

Methodologically, Brahe’s biographers and historians have tended to focus on the man and his writings: yet until recently none specifically focused on his ever-changing familia (family) of research assistants that passed through Hven. John Robert Christanson’s book “On Tycho’s Island: Tycho Brahe and His Assistants 1570-1601” (Cambridge University Press, 2000) changed all that: what started out (quite literally) as Christianson’s shoe-box of notecards to pull together the numerous fragmentary mentions of Brahe’s coworkers slowly grew into a database, and then (25 years on) into the present book.

But there’s a problem: however interested you are in the subject, after a while the database-like origins of the book – in the infinitessimal ebbs and flows of the set of assistants – start to grate on the reader. And let’s face it, what Brahe was running was as much a kind of “observation factory” as anything else, turning (taking a Marxist-Leninist spin) a input stream of idealistic researchers into a output stream of data. After around 150 pages of on-island minutiae, you start to wonder: where is this all going? How much more can I take?

And then on page 171, Christianson’s book explodes in a direction you simply won’t (unless you’re extraordinarily well-read on Brahe’s life) have seen coming. Brahe tries to marry off his eldest morganatic daughter (“morganatic” means that when a nobleman marries a commoner, his children won’t inherit his nobility or money) to Gellius Sascerides, a clever (but church-mouse poor) member of his familia. And then everything – and I mean everything – starts to go wrong for Brahe (and at some speed), to the point that he ends up dismantling his beloved observatory and fleeing the country. Thanks to his Europe-wide network of contacts (particularly Tadeas Hajek), he finally ended up working for Holy Roman Emperor Rudolf II in Prague (though only briefly) – but even so, Brahe’s swings in fortune are really quite staggering.

It’s only once you reach the end of the book that you can appreciate what happened in terms of his two familiae. Given that neither his morganatic children nor his set of researchers and coworkers seemed likely to him to give him the continuing legacy he desired, what was Brahe to do? He tried to finesse a best-of-both-worlds scenario, but the attempted union of his morganatic family and his (almost adoptive) intellectual family was simply never going to work within his societal context. It is only really a proper appreciation for his constellation of assistants on Hven that gives his whole story poignancy.

Writing teachers often say that the beginning of a story is rarely the best place to start: and so many writers would start “Brahe: The Novel” with the attempted negotiations for the wedding (and bring in all the preceding history in flashbacks etc), because this is where the wedding train (sorry!) starts to come off the rails – and where oh-so-controlling Brahe begins to lose the plot. Yet what Christianson has produced is rather more valuable than a novel: a rich, dense, vividly-detailed historical stage upon which the reader can imagine and construct their own dramas.

Overall verdict: Highly Recommended (but don’t give up in the middle!)

Review of "Inventing The Flat Earth"…

by ⋅ Leave a Comment

It’s a mystery: when there is abundant evidence that people in the Middle Ages knew for sure that the earth was basically spherical, why has the myth persisted until the late 20th century that Columbus had to argue against Flat Earth proponents to gain backing for his voyage? And where did this whole mythology come from?

In his fascinating (if all too brief) “Inventing The Flat Earth” (1991), medieval historian Jeffrey Burton Russell traces the faulty arguments and ideologies across the centuries that contributed to this nonsense. As an immediate cause, he points to a small coterie of 19th century writers (specifically William Whewell (1794-1866) and John W. Draper (1811-1882)) who decided to start an agitprop war between “religion” and “science”, essentially by building opposing false idols of both “sides” and getting people angry enough about it to join in the fight.

For “religion”, the caricature they constructed was one of superstition and medieval backwardness: and what (thanks to multiple careful misreadings of the sources) could be more retrogressive than the notion of the flat earth? Disregarding the fact that just about everyone at that time believed in a spherical earth, Church or not. *sigh*

Yet for retrogressivity to be of interest as something to avoid, someone had (logically) to be promoting progressivity: Russell traces this back to Hegel, Auguste Comte, and to Jules Michelet, the last of which dubbed medieval scholastics “valiant athletes of stupidity” (hugely unfairly, of course).

But Jeffrey Burton Russell goes back further still: calling the Middle Ages “the Middle Ages” is a way of implicitly saying that it sat inbetween the (glorious) Classical Era and the (glorious) Renaissance – that it was a Tweenie era, that was more than just a bit disappointing and dull. And similarly with the Dark Ages, which would appear to have been so hugely disappointing that some extreme revisionist historians are trying to excise it completely!

Ultimately, Russell points the finger at Renaissance myth-makers: it was they who essentially invented the whole “medieval = rubbish” mythology which used to annoy Lynn Thorndike so much (though perhaps he should have been angrier with Alberti & his chums than with Jacob Burckhardt), in order to justify their own glory, as if fama was a zero-sum game. What did those Renaissance brainiacs ever do for us, eh?

Rewind to 1492, and the basic history is that Columbus never had to argue against a flat earth. His main point of disagreement was with those scientifically-minded people of the time who argued (completely correctly!) that his estimate of the distance East West to the Orient was far too low, and that he and his crew would die of starvation before they reached there. And they would have done, had another continent not happened to be in the way… but that’s another story.

Some may have heard of this book via the recent short article by Mano Singham (Phi Delta Kappan, 1st April 2007, available online) that was built almost entirely around a high-speed precis of Russell’s book: on HASTRO-L (2nd December 2007), Michael Meo criticized Singham’s presentation, but I think the inaccuracies there were in the summarizing, not in the original.

As far as the intellectual history goes, the seed of the myth/error seems to have been specifically sown by Copernicus in his De Revolutionibus preface (not the one Osiander added!). There, he says:-

For it is not unknown that Lactantius, otherwise an illustrious writer but hardly an astronomer, speaks quite childishly about the earth’s shape, when he mocks those who declared that the earth has the form of a globe. Hence scholars need not be surprised if any such persons will likewise ridicule me.

Copernicus was trying to play to the Church audience here, as the spherical earth was so well-believed as to be a point of faith. Yet because Lactantius’ opposing view (of a flat earth) had been deemed heretical, the papacy ordered in 1616 that this passage be censored from Copernicus’ book – but this order came too late for the 3rd edition of 1617, and the subsequent edition came along only in 1854.

And so the final irony here is that if De Revolutionibus had indeed (as Koestler asserted) been “The Book Nobody Read”, the flat-earth myth/error might never have flowered.

Review of "The Book Nobody Read"…

by ⋅ 2 Comments

In his 1959 book “The Sleepwalkers”, Arthur Koestler painted a rather damning picture of Renaissance European astronomers and scientists, where the only person not sleepwalking was Kepler. As part of the process of tarring everyone else with the same soporific brush, Koestler derided Copernicus’ famous “De Revolutionibus” as “The Book Nobody Read“.

It’s true that only a small proportion of “De Revolutionibus” is particularly interesting, with the remainder filled with bone-dry technical astronomical gubbins. But people manifestly did read it, often adding their comments (thoughts, possible errors in the text, etc) in the margins. And what might you learn about that community of readers by examining the marginalia in every extant copy?

More than 30 years ago, Owen Gingerich, one of the leading historians of astronomy, took up this challenge, and in so doing compiled an international census of all the first and second edition copies of Copernicus’ book. “The Book Nobody Read” is Gingerich’s personal memoir of his extraordinary (if obsessive) historiographical / bibliomanic quest to rebut Koestler’s dismissive epithet. Oh: and of course, it turns out that lots of people did read De Revolutionibus.

Throughout the memoir, Gingerich’s perpetually boyish enthusiasm for this prolonged pursuit shines through: yet even an ardent astro-aficionado with a codicological bent (such as, errrrm, me) must silently shudder at the extreme degree to which this sheer marginality was doggedly followed.

Probably the best sections of the book are the legal bits, where FBI personnel step into the frame, invariably on the trail (thanks to Gingerich’s book measurements and lists of missing or altered pages) of various purloined copies of De Revolutionibus, along with the corresponding courtroom sequences. There are also some choice footnotes which connoisseurs of that genre will enjoy, particularly the one on p.187 about Kepler’s apparent seven-and-a-half month gestation (he was sure he was conceived on his parents’ wedding night!)

As a personal account, it’s only superficially autobiographical: while the reader does build up an idea of the development of Copernican scholarship over the three decades covered, and a few hints at an ongoing academic spat with fellow historian Ed Rosen, Gingerich himself is largely backgrounded by the tidal wave of historiographical facts he feels compelled to share.

Yet at its heart, the book has an internal paradox: that while its structure is not unlike a polite, slightly clunky, pre-Cold War 1950s time-capsule, the thinking inside it has an tight, inclusive, late 1990s academic sensibility. Ultimately, I wanted to know whether this was a portrait of the Census, or a portrait of Gingerich himself: but it is never really clear which.

I really enjoyed “The Book Nobody Read” (and if you’re a regular Voynich News reader, you’d probably enjoy its ‘book detective’ sleuthing just as much as I did): it reads well and is engaging throughout, so all credit to its author. Yet it takes a certain type of personality to bare not just your activities in a book, but your soul as well: and the former dominates the latter here. Ultimately, it’s a biography of the Census, not of Gingerich: as a result, I think some readers may well come away from this bookish feast slightly hungry, which is a shame.

"The Invention of the Telescope" update…

by ⋅ Leave a Comment

OK, so it’s not exactly Wikileaks: but following on from my very recent review of Albert van Helden’s monograph, a (how shall I put it?) well-placed insider has dropped me a line…

Apparently, the American Philosophical Society is planning to republish “The Invention of the Telescope” in an “augmented edition” next year (2009, the International Year of the Telescope), for which van Helden has been asked to put together a new introduction. My guess is that this will come out at about the same time as the book on Galileo’s sunspots which Eileen Reeves and van Helden have been working on (which itself was delayed by Reeves’ “Galileo’s Glassworks“, according to her acknowledgments section).

However, I should flag that a big problem with long publishing pipelines like this is that it only takes one really interesting piece of work to come out to make everything in it seem instantly outdated: and with the 400th anniversary of Galileo’s telescopic breakthroughs imminently upon us, right now there are doubtless several (2? 5? 10?) historians out there finishing up their shocking alt.history revisionist accounts of the telescope’s genesis.

For me, the most surprising aspect of this whole story is that van Helden’s work has lasted 31 years without being significantly overturned (as far as I can see): but in the field of ideas, things can change (and they often do, rapidly). We shall see what happens next…

Incidentally, I wish I knew of a book like the first half of “Galileo’s Glassworks” that covered the literary prehistory of the microscope, and/or an equivalent of van Helden’s monograph covering the microscope’s birth. Was the romantic lure of seeing tiny things ever as great as that of seeing afar?

All of a sudden, I’m transported Proust-like to the Trigan Empire comic strip in the “Look & Learn”s of my childhood, where one storyline revealed whole subatomic galaxies to explore (might Oli Frey have drawn that?)…

Review of "The Invention of the Telescope"…

by ⋅ Leave a Comment

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"…

by ⋅ Leave a Comment

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.