Stephen Johnston
@stephenaj.bsky.social
Curator Emeritus at Oxford's History of Science Museum; STEM historian, particularly instruments and material culture - current research focused on astrolabes and astrology in medieval and renaissance Europe. (Disclaimer: focus known to wander.)
Very interesting, and I've just registered - but is it really hybrid? The booking and confirmation pages only give a physical venue (and I'll be in Oxford...)
January 26, 2026 at 1:46 PM
Very interesting, and I've just registered - but is it really hybrid? The booking and confirmation pages only give a physical venue (and I'll be in Oxford...)
Reposted by Stephen Johnston
Reposted by Stephen Johnston
Unfolding the multiple lives of a shipbuilding manuscript: Our first Artefact of the Month in 2026 is known as 'Fragments of Ancient English Shipwrighty' and reveals the interactions between mathematics and practice in the Scientific Revolution:
uhh.de/csmc-aom-35
uhh.de/csmc-aom-35
January 15, 2026 at 3:30 PM
Unfolding the multiple lives of a shipbuilding manuscript: Our first Artefact of the Month in 2026 is known as 'Fragments of Ancient English Shipwrighty' and reveals the interactions between mathematics and practice in the Scientific Revolution:
uhh.de/csmc-aom-35
uhh.de/csmc-aom-35
Can't resist adding: turns out that the NAL also has a separate copy of the sale catalogue, which is bound with the list of prices and buyers that was printed after the sale. Yes, you even got to see who bought things back in those days! (Though you had to pay for the privilege by subscribing....)
January 8, 2026 at 12:39 PM
Can't resist adding: turns out that the NAL also has a separate copy of the sale catalogue, which is bound with the list of prices and buyers that was printed after the sale. Yes, you even got to see who bought things back in those days! (Though you had to pay for the privilege by subscribing....)
Visiting to see a specific auction catalogue ahead of a #TopSecret mission later this month. So, for now, all I can say is: check out the switch for the reader lamp in the background - maybe it's actually older than this set of all the Sotheby's London sale catalogues from May 1957?!
January 8, 2026 at 12:39 PM
Visiting to see a specific auction catalogue ahead of a #TopSecret mission later this month. So, for now, all I can say is: check out the switch for the reader lamp in the background - maybe it's actually older than this set of all the Sotheby's London sale catalogues from May 1957?!
First ever visit to the National Art Library www.vam.ac.uk/info/nationa... at the V&A Museum. Cheapskate tip: register in advance, pick up your reader card and only then go to the cloakroom to hand in your bag - now for free.
January 8, 2026 at 12:39 PM
First ever visit to the National Art Library www.vam.ac.uk/info/nationa... at the V&A Museum. Cheapskate tip: register in advance, pick up your reader card and only then go to the cloakroom to hand in your bag - now for free.
Ah. Found corsair.themorgan.org/vwebv/search.... I didn't know Caesius was a cognomen of Blaeu...
corsair.themorgan.org
January 8, 2026 at 10:32 AM
Ah. Found corsair.themorgan.org/vwebv/search.... I didn't know Caesius was a cognomen of Blaeu...
Very nice - is that Jan Jansson? 30 years later and with print on pasteboard rather than manuscript on parchment. (I should really have tagged #volvelles and #astrolabes originally.)
January 8, 2026 at 10:03 AM
Very nice - is that Jan Jansson? 30 years later and with print on pasteboard rather than manuscript on parchment. (I should really have tagged #volvelles and #astrolabes originally.)
Timeline cleanse: #OTD 2016 at the British Library to view these extraordinary objects (other reader for scale). I first saw them in 1997 in the old BL MSS Room and finally published '"Preciseness and Pleasure": The Astrological Diptychs of Thomas Hood' in 2018 in doi.org/10.1163/9789...
January 8, 2026 at 9:40 AM
Timeline cleanse: #OTD 2016 at the British Library to view these extraordinary objects (other reader for scale). I first saw them in 1997 in the old BL MSS Room and finally published '"Preciseness and Pleasure": The Astrological Diptychs of Thomas Hood' in 2018 in doi.org/10.1163/9789...
👏 for teamwork: I only got the @dbellingradt.bsky.social joke/reference when I saw your neat addition of the hat. Clearly it's good to spell things out for this more pedestrian soul at the back (or, more self-charitably, for those on a visual rather than verbal wavelength....)
January 8, 2026 at 8:04 AM
👏 for teamwork: I only got the @dbellingradt.bsky.social joke/reference when I saw your neat addition of the hat. Clearly it's good to spell things out for this more pedestrian soul at the back (or, more self-charitably, for those on a visual rather than verbal wavelength....)
I recall an acerbic take on the little that is genuinely known about her, by David King - but where did he write this? Must be somewhere in his voluminous publications on davidaking.academia.edu/research. Almost certainly a section of a larger text rather than a dedicated piece. Good luck!
David A King
davidaking.academia.edu
January 8, 2026 at 12:48 AM
I recall an acerbic take on the little that is genuinely known about her, by David King - but where did he write this? Must be somewhere in his voluminous publications on davidaking.academia.edu/research. Almost certainly a section of a larger text rather than a dedicated piece. Good luck!
The annotated husband and wife Rantzau tract! ❤️
Today is Epiphany/Three Kings day, and to celebrate, @sibyllacumae.bsky.social and I just sent the newest issue of our newsletter, focusing On Astrology. Share, read, enjoy - it's free! 📜 #bookhistory #booksky #libsky #rarebooks #astronomy 🗃️🔭 #histSTM open.substack.com/pub/twohalfs...
On Astrology
Putting the (s?)ass in astrology
open.substack.com
January 6, 2026 at 7:54 PM
The annotated husband and wife Rantzau tract! ❤️
I loved the image at first sight but couldn't immediately fathom how it was created. Now there is a wonderfully clear thread to explain the kit and process, with the bonus of a hi-res zoomable version at the end. Hmm, could I print out a large version to go on the wall? (Or a backlit transparency?!)
Since posting this 2025 year-long keogram, there have been quite a few questions asking how it was created and what is visible. In this thread I'll try to explain how it all works.
January 6, 2026 at 2:49 PM
I loved the image at first sight but couldn't immediately fathom how it was created. Now there is a wonderfully clear thread to explain the kit and process, with the bonus of a hi-res zoomable version at the end. Hmm, could I print out a large version to go on the wall? (Or a backlit transparency?!)
Reposted by Stephen Johnston
Happy new year! My all sky camera imaged the sky every 15 seconds and this picture shows what happened in the sky in 2025. It shows the length of the night and day with the hourglass shape, the monthly lunar cycle with the diagonal bands, the elevation of the Sun at local noon, and lots of clouds.
January 1, 2026 at 8:54 PM
Happy new year! My all sky camera imaged the sky every 15 seconds and this picture shows what happened in the sky in 2025. It shows the length of the night and day with the hourglass shape, the monthly lunar cycle with the diagonal bands, the elevation of the Sun at local noon, and lots of clouds.
Reposted by Stephen Johnston
Just shared by Samuel Gessner @sgessner.bsky.social via the Rete mailing list:
The great programme of the international conference “Beyond Books: Instruments and Knowledge in #Libraries”, 14–15 January 2026 at @mhngeneve.bsky.social.
#histstm #histsci #medievalsky
@stephenaj.bsky.social
The great programme of the international conference “Beyond Books: Instruments and Knowledge in #Libraries”, 14–15 January 2026 at @mhngeneve.bsky.social.
#histstm #histsci #medievalsky
@stephenaj.bsky.social
January 5, 2026 at 11:18 AM
Just shared by Samuel Gessner @sgessner.bsky.social via the Rete mailing list:
The great programme of the international conference “Beyond Books: Instruments and Knowledge in #Libraries”, 14–15 January 2026 at @mhngeneve.bsky.social.
#histstm #histsci #medievalsky
@stephenaj.bsky.social
The great programme of the international conference “Beyond Books: Instruments and Knowledge in #Libraries”, 14–15 January 2026 at @mhngeneve.bsky.social.
#histstm #histsci #medievalsky
@stephenaj.bsky.social
And an interesting skyscape too, which seems plausible when modelled with Alex Boxer's online astrolabe. Does the text give the date when the comet was first seen in Antwerp, or explicitly give a date for its image? (Sunset on 15/11/1577 works well.) And I imagine the comet was then in Capricorn?
December 31, 2025 at 9:39 AM
And an interesting skyscape too, which seems plausible when modelled with Alex Boxer's online astrolabe. Does the text give the date when the comet was first seen in Antwerp, or explicitly give a date for its image? (Sunset on 15/11/1577 works well.) And I imagine the comet was then in Capricorn?
Reposted by Stephen Johnston
The call for the 2026 Training Week: Global History of Astronomy on Primary Sources – A Focus on Cosmology, Physics and Astrology is now open! eida.hypotheses.org/seminars-2/2...
June 8-12 2026
Bibliothèque nationale de France, Observatoire de Paris
Deadline: 30/01/26 #historyofastralsciences
June 8-12 2026
Bibliothèque nationale de France, Observatoire de Paris
Deadline: 30/01/26 #historyofastralsciences
December 17, 2025 at 5:35 PM
The call for the 2026 Training Week: Global History of Astronomy on Primary Sources – A Focus on Cosmology, Physics and Astrology is now open! eida.hypotheses.org/seminars-2/2...
June 8-12 2026
Bibliothèque nationale de France, Observatoire de Paris
Deadline: 30/01/26 #historyofastralsciences
June 8-12 2026
Bibliothèque nationale de France, Observatoire de Paris
Deadline: 30/01/26 #historyofastralsciences
Just started a week ago. Imported all my albums and playlists from Spotify without a hitch, and works well so far. I signed up for the free trial via the Android app, but it would be better to do so via the web, to avoid future Google Play 15% fees (and presumably the same with the Apple Store).
December 15, 2025 at 12:23 AM
Just started a week ago. Imported all my albums and playlists from Spotify without a hitch, and works well so far. I signed up for the free trial via the Android app, but it would be better to do so via the web, to avoid future Google Play 15% fees (and presumably the same with the Apple Store).
As the other external committee member with @eleonoraandriani.bsky.social I'm also hugely looking forward to the results of this doctoral project over the next few years - it will be genuinely fascinating to see the Escorial manuscript deeply investigated and fully unveiled.
Honoured to be part of the doctoral committee for this project at Hasselt University. Read more here: www.uhasselt.be/nl/over-uhas... #historyofastronomy #historyofscience
December 2, 2025 at 3:35 PM
As the other external committee member with @eleonoraandriani.bsky.social I'm also hugely looking forward to the results of this doctoral project over the next few years - it will be genuinely fascinating to see the Escorial manuscript deeply investigated and fully unveiled.
But your St Germain example looks like they are also representing the winds, as they also sometimes appear on ivory diptychs (where it often looks more like they are suffering from food poisoning.). And they are frequently on early printed maps too: oculi-mundi.com/windheads
The history of wind head iconography on old maps
windhead, mapmaking, cartography, decoration, iconography, allegory, study of images, study of maps, representation, maps, symbols, meteorology, artistry
oculi-mundi.com
November 20, 2025 at 11:58 AM
But your St Germain example looks like they are also representing the winds, as they also sometimes appear on ivory diptychs (where it often looks more like they are suffering from food poisoning.). And they are frequently on early printed maps too: oculi-mundi.com/windheads
And why my diptych dial example? There was a long tradition of cherub heads with wings in the corners of clock faces. Here they are on the dial of a long case clock by Ahasuerus Fromanteel, London, c. 1665. They're also found well into the 18th century (later too?).
(Alt text for image source.)
(Alt text for image source.)
November 20, 2025 at 11:58 AM
And why my diptych dial example? There was a long tradition of cherub heads with wings in the corners of clock faces. Here they are on the dial of a long case clock by Ahasuerus Fromanteel, London, c. 1665. They're also found well into the 18th century (later too?).
(Alt text for image source.)
(Alt text for image source.)
I think the zodiac must be (at best) suggestive: I can't see how it could have astronomical meaning. (Aries at 6 o'clock would be better since when the Sun enters Aries it's dawn at 6 am.) But perhaps the zodiac iconography would have been seen as reassuringly traditional in 1827?
November 20, 2025 at 11:58 AM
I think the zodiac must be (at best) suggestive: I can't see how it could have astronomical meaning. (Aries at 6 o'clock would be better since when the Sun enters Aries it's dawn at 6 am.) But perhaps the zodiac iconography would have been seen as reassuringly traditional in 1827?
Interesting that almost everything else visible here is quite austere, yet the clock face uses the traditional zodiac as decoration. And cute that there are heads of the winds in the spandrels, and they don't all seem to be suffering from the apparent nausea that commonly afflicts them....
November 19, 2025 at 7:35 PM
Interesting that almost everything else visible here is quite austere, yet the clock face uses the traditional zodiac as decoration. And cute that there are heads of the winds in the spandrels, and they don't all seem to be suffering from the apparent nausea that commonly afflicts them....
How on earth did I manage to overlook that? 🙄 Not much of an advert for eye-balling on my part....
November 19, 2025 at 3:50 PM
How on earth did I manage to overlook that? 🙄 Not much of an advert for eye-balling on my part....
Hope you enjoy it!
November 19, 2025 at 3:27 PM
Hope you enjoy it!