Nikephorus Gregoras and Astrolabes

My interest in Byzantine science began with a text, Nikephorus Gregoras’s “περὶ κατασκευῆς καὶ γενέσεως ἀστρολάβου” (“On the Mathematical Origin and Construction of the Astrolabe”). Gregoras was renowned for his skill in both mathematics and the sciences of the stars. He was favored by emperors and helped reestablish the sciences in 14th-century Constantinople. Yet, at first glance the content and form of his text on the astrolabe seems relatively simple, especially compared to the texts circulating in Arabic and Latin. He must have known of these other traditions.

Why then did he write this text?
Who was his intended audience?
How did a text on the astrolabe advance his goals?
Or why did he think a text on the astrolabe would advance his goals?

Gregoras’s offer a glimpse of the cultural and scientific values of 14th-century Constantinople and the imperial court. What began (and continues) as a study of a text has become an examination of the scientific culture in the imperial capital.

Nicephorus Gregoras’s “περὶ κατασκευῆς … ἀστρολάβου”

December 23, 2016

A nice drawing of the rete from Nicephorus Gregoras’s “περὶ κατασκευῆς καὶ γενέσεως ἀστρολάβου” (“On the Mathematical Origin and Construction of the Astrolabe”). This rete, like other diagrams in copies of Gregoras’s text, lacks stars and finer details. In the few copies I’ve seen that include the stars, the rete… Read more

A Wolf-Headed Byzantine Veterinarian

December 21, 2016

The Hippiatrica assembles treatments for a wide range of ailments and injuries horses might suffer. The work itself is a collection from various other treatises by authors—e.g., Eumelos, Apsyrtos, Anatolios, Pelagonius, Themnestos, and Hierocles—and was probably assembled sometime between the 5th and the 10th centuries. In this illustration from a… Read more

Byzantine Structure of the Cosmos

December 19, 2016

This diagram showing the structure of the cosmos comes from Nicephorus Blemmydes’ “Epitome physica.” At the center is the sphere of elemental earth surrounded by a narrow sphere of water. Then a broad sphere of air surrounds them capped by the sphere of fire. Separating the elements from the heaves… Read more

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