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.

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.

I’ve been reading up on the pre-history of the telescope recently (hence my reviews of Eileen Reeves’ Galileo’s Glassworks and Albert van Helden’s The Invention of the Telescope), but have omitted to mention why I thought this might be of relevance to the Voynich Manuscript.

The answer relates to Richard SantaColoma’s article in Renaissance Magazine #53 (March 2007) with the title “The Voynich Manuscript: Drebbel’s Lost Notebook?”, which claimed to find a persuasive familial similarity between the curious jars arranged vertically in the pharma sections and Renaissance microscopes, specifically those described or designed by Cornelius Drebbel. His (updated) research also appears here.

The biggest problem with Voynich hypotheses is that, given 200+ pages of interesting stuff, it is comparatively easy to dig up historical evidence that appears to show some kind of correlation. In the case SantaColoma’s webpage, this category covers the stars, the hands, braids, caps, colours, four elements, Francis Bacon’s New Atlantis and handwriting matches suggested: none of these is causative, and the level of correlation is really quite low. All of which is still perfectly OK, as these parallels are only presented as suggestive evidence, not as any kind of direct proof.

It is also tempting to use a given hypothesis to try to support itself: in the 1920s, William Romaine Newbold famously did this with his own circular hypothesis, where he said that the only way that the manuscript’s microscopic cipher could have been written was with the aid of a microscope, ergo Roger Bacon must have invented the microscope. All false, of course. Into this second category falls the “cheese mold”, “diatoms” and “cilia” of SantaColoma’s webpage: if these are to used as definitive proof of the presence of microscopy in the VMs, the level of correlation would need to be substantially higher. But these parallels are, once again, only presented as suggestive evidence, not proof.

Strip all these away, and you’re still left with the real meat of SantaColoma’s case: a set of striking similarities between 17th century microscopes and the curious devices in the Voynich Manuscript’s pharma section. Even if (as I do) you doubt that all the colouring on the pages was original (and upon which some of SantaColoma’s argument seems to rest), it’s an interesting observation.

Having said that, no actual proof or means of proof (or disproof) is offered: it is just a set of observations, resting upon a relatively little-tested tranche of history, that of the microscope. Can we do better? I think we can.

Firstly, modern telescope historians (I’m thinking of Albert van Helden here, though he is far from alone in this respect) now seem somewhat dubious of the various Janssen family claims: and so I’m far from comfortable with placing the likely birth of the microscope with the Janssens in 1590. As Richard SantaColoma points out, Cornelius Drebbel is definitely one of the earliest documented microscope makers (from perhaps a little earlier than 1620, but probably not much before 1612, I would guess).

Secondly, it is likely that the power of the lenses available for spectacles pre-1600 was not great: Albert van Helden calculated that a telescope made to della Porta’s (admittedly cryptic) specification could only have given a magnification of around 2x, which would be no more than a telescopic toy. I would somewhat surprised if microscopes constructed from the same basic components had significantly higher magnification.

Thirdly, the claimed presence of knurled edges in the VMs’ images would only make sense if used in conjunction with a fine screwthread, to enable the vertical position of an element along the optical axis to be varied: but I’m not sure when these were invented or adapted for microscopes.

All in all, I would assert that if what is being depicted in the VMs’ pharma section is indeed microscopes from the same family as were built by Drebbel from (say) 1610 onwards, there would seem no obvious grounds for dating this to significantly earlier than 1610: even if it all came directly from Della Porta, around 1589 would seem to be the earliest tenable date.

The problem is that there is plenty of art historical data which places the VMs circa 1450-1500: and a century-long leap would seem to be hard to support without more definitive evidence.

As always, there are plenty of Plan B hypotheses, each of which has its own unresolved issues:-
(a) they are microscropes/telescopes, but from an unknown 16th century inventor/tradition
(b) they are microscropes/telescopes, but from an unknown 15th century inventor/tradition
(c) they’re not microscopes/telescopes, they just happen to look a bit like them
(d) they’re not microscopes/telescopes, but were later emended/coloured to look like them
(e) it’s all a Dee/Kelley hoax (John Dee was Thomas Digges’ guardian from the age of 13)

Despite everything I’ve read about the early history of the telescope and microscope, I really don’t think that we currently can resolve this whole issue (and certainly not with the degree of certainty that Richard SantaColoma suggests). The jury remains out.

But I can offer some observations based on what is in the Voynich Manuscript itself, and this might cast some light on the matter for those who are interested.

(1) The two pharma quires seem to be out of order: if you treat the ornate jars as part of a visual sequence, it seems probable that Q19 (Quire 19) originally came immediately before Q17 in the original binding.

(2) The same distinctive square “filler” motif appears in the astronomical section (f67r1, f67r2, f67v1), the zodiac section (Pisces, light Aries), the nine rosette page (central rosette), and in a band across the fifth ornate jar in Q19. This points not only to their sharing the same scribe, but also to a single (possibly even improvised) construction/design process: that is, the whole pharma section is not simply a tacked-on addition, it is an integral part of the manuscript.

(3) Some paint on the pharma jars appear original: but most seems to be a later addition. For example: on f99v, I could quite accept that the palette of (now-faded) paints used to colour in the plants and roots was original (and I would predict that a spectroscopic or Raman analysis would indicate that this was probably comprised solely of plant-based organic paints), which would be consistent with the faded original paint on the roots of f2v. However, I would think that the bolder (and, frankly, a little uglier) paints used on the same page were not original.

Put all these tiny fragments together, and I think this throws doubt on one key part of SantaColoma’s visual argument. He claims that the parallel hatching inside the ornate jar at the top of f88r (the very first jar in Q17) is a direct indication that it is a lens we are looking at, fixed within a vertical optical structure. However, if you place Q19 before Q17 (as I believe the original order to have been), then a different story emerges. The ten jars immediately before f88v (ie at the end of Q19) all have vertical parallel hatching inside their tops, none of which looks at all like the subtle lens-like shading to which SantaColoma is referring. For reference, I’ve reproduced the tops of the last four jars below, with the final two heavily image-enhanced to remove the heavy (I think later) overpainting that has obscured much of the finer detail.

This is the “mouth” of the top jar on f102r: the vertical parallel hatching seems to depict the back wall of a jar, ending in a pool of faintly-coloured yellow liquid (probably the original paint).

 

This is the mouth of the bottom jar on f102r, which appears to have vertical parallel hatching right down, as though the jar is empty near the top (or perhaps its contents are clear).


This is the top jar on 102v, enhanced to remove the paint. I think some vertical hatching is still visible there: it would take a closer examination to determine what was originally drawn there.

This is the bottom jar on f102v, again heavily enhanced to remove paint. Vertical hatching of some sort is visible.

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?)…

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.

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 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…

To mark the four hundredth anniversary next year of Galileo’s first astronomical use of the telescope in 1609, the IAU has designated 2009 “The International Year of Astronomy” (IYA2009): which is likely to be the trigger for a glut of telescope history-themed books (probably no bad thing, in my opinion). But what happened before 1609?

I recently mentioned here “the lost 150 years”, that awkward pause between the widespread availability of both convex and concave lenses (circa 1450) and the appearance of microscopes (circa 1590) and telescopes (circa 1600). Such compound optical devices could have been invented by anyone during that period, and the best-documented pre-1600 telescopic claim so far seems to be from Thomas Digges (John Gribbin discusses this in one of his books). But could yet other inventors (such as possibly the author of the Voynich Manuscript) have pre-dated Digges, Janssen and co?

There were plenty of alchemical-style claims to that effect, most notably from H. C. Agrippa, who wrote in his “Occult Philosophy” that “And I knew how to make by them wonderful things, in which any one might see whatsoever he pleased at a long distance” (Book II, Chapter 23) . However, there was (in this case) apparently nothing of real substance behind his bluster.

All the same, I asked on the HASTRO-L mailing list if there were any up-to-the-minute books on this far-too-quiet period, and was delighted to learn (via Peter Abrahams) of a book that is just coming out from Harvard University Press: “Galileo’s Glassworks, The Telescope and the Mirror” (2008), by Eileen Reeves, Associate Professor of Comparative Literature at Princeton, who specialises in the study of early modern scientific literature. Though the publisher’s blurb seems to make her book sound over-focused on the minutiae of Galileo’s rhetoric, I’m assured that its first half does actually take in the wider pre-1609 field of view (which is precisely what I was most interested in).

The release date for Glassworks is either January 2008 or 28th February 2008 (depending on who you ask): there are already some copies for sale in the US, but it’s only pre-ordering in the UK at the moment. I’ll review it here when my copy arrives (counting the days)…

Just mooching around the web looking for Trithemius-related stuff (as you do), I saw a reference to Renaissance “telescopes, microscopes and bezicles” in the first (free) page of Polygraphia and the Renaissance sign: The case of Trithemius, from the Springer journal Neophilologus. I had never heard of “bezicles”, so decided to have a sniff around, see what I was missing.

It turns out that the author meant the (more modern French) “besicles“, meaning ‘spectacles‘ (though people usually say lunettes): there’s a glossary of spectacles terms here. Now: besicles was originally bericles, where the ‘r’ somehow transformed into ‘s’ over the centuries (but you’d have to ask a linguist about this subtle shift). And bericles was in turn from beryl, a “smoke-coloured stone” (according to this fun page on spectacles history) used to grind the lenses from – although pure beryl is colourless, & it is the impurities in it which give it colour.

There’s a bigger article on spectacles in the American Journal of Gastroenterology (yes, really!), though you’d need to pay to read it (boo, hiss).