The Traveling Astrolabe
Bringing People Together Through Science
The Tool
Astrolabes are a mix of scientific instrument, magic decoder, and artwork. It’s made of a disk called a mater, which can be made of any material and be any size, and is lined with time measurements. Nested in the mater is a disk with a plate with the earth’s latitudinal lines projected over it. The third plate, over the map, is called the ‘rete’ and has well-known celestial bodies. A straight edge goes over the rete to point at a time measurement on the mater, and a siting tool that can pivot sits on the back of the whole contraption.
This disk is supposed to find the position of a planet or star, survey properties, find the latitude on land given the time of day, and triangulate between places. It was used for many more jobs starting in Ancient Greece, and they became both wide-spread tools and marks of scholarship throughout the Middle East and Europe, on display through the Middle Ages right up until the sextant started to do its job.
This Astrolabe
This particular astrolabe, called the Verona Astrolabe, is made of brass and is not particularly large. What is special about it is that it has been written all over by many people.
It was made in Al-Andalus in the 1000’s, and it was changed over time as each new person used it. It originally had prayer lines and names so the owner could time his prayers, and a disk for stars that can be seen in North Africa was added when the owner moved there.
Mostly, though, the thing that changed was the writing on it.
The Many Hands It Passed Through
The original owner seems to have been in Toledo, but at some point, a gentleman named Yunus offered it to another named Ishaq and wrote their names on it. Since these are Jewish names, it probably had passed to the Jewish Diaspora.
Then someone tried to correct the time measurements on the Mater. Whoever did it was wrong about the measurements and seems to have been ignored.
Not ignored were Hebrew translations of Arabic names for astrological signs and numbers that the new owners wrote under the originals.
Then the astrolabe landed in Verona, Italy. There was a thriving Jewish community there, and there is a famous treatise on how to use an astrolabe in circulation at the same time this particular astrolabe was in use. It would not be out of question that Yunus and Ishaq moved there and used the treatise for the astrolabe.
In the 1600’s, it arrived at the doorstep of Ludovico Moscardo, a wealthy gentleman of Verona who had an impressive collection of art and gadgets. His descendants married into the Miniscalchi family. They continued to fly high and hold onto the astrolabe until the founded the Fondazione Museo Miniscalchi-Erizzo to hold all the neat stuff they had.
The museum didn’t recognize its history and buried it in the back of the rooms. It was pretty, but not important. They uploaded a picture of it on the internet a few years back, since it had never been on display before.
That brought it to the attention of Dr Frederica Gigante, whose personal jam is art history and materials that traveled between the Middle East and Europe. She immediately begged to see it in person, and they let her. It is still in the Verona museum, but it is now on proud display on their shelves.
Conclusion
There’s something touching about a tool that passes from Muslim to Jew to Christian. Regardless of what else they believe, they all are under the same stars, and we are still in some small way always in touch with everyone else, across the miles and centuries.
Of course, Dr Gigante’s papers are all about the connections we make across boundaries. It’s good to know that we were interlocked with each other then as now.
Sources:
https://www.hist.cam.ac.uk/people/dr-federica-gigante
https://brill.com/view/journals/nun/39/1/article-p163_9.xml