Recent posts

Byzantine Astrolabe (sort of)

January 20, 2020

In a fragment attributed to John Kamateros on the astrolabe are a handful of interesting diagrams illustrating the various parts of an astrolabe. Here is the diagram showing the rete. There is also diagram illustrating the plate, and two showing different aspects of the back of the instrument. Read more

Galileo In Vienna

January 17, 2020

In Vienna’s 13th district stands a beautiful Jugendstil building, the Galileihof. Designed by and built by Emil Reitmann in 1905, the building appears to have been renovated not long ago. Vienna is strangely committed to Galileo. In addition to the Galileihof, on the other side of town is the Galileigasse,… Read more

Portrait of a Mathematician

January 14, 2020

The label identifies this painting as a portrait of Pierre Joseph de Rivaz, an 18th-century “Swiss mathematician, inventor and historian.” Rivaz is not particularly famous, and seems to be better known for his inventions than his mathematical achievements. Nonetheless, the label claims this is a “Portrait of a Mathematician.” Although… Read more

Want to learn what an astrolabe is?
Want to learn how to operate one?
Download my introduction to the history and use of the astrolabe:
An Introduction to the Astrolabe