Representation of Euclid and the 11th-century astronomer Herman Dalmatin (also called Herman of Carinthia). 'Two persons seated: "Euclides", on the dexter side, uplifts a sphere with his right hand, and with his left holds a telescope, through which he is observing the stars; toward whom "Hermannus", on the other side, holds forth a circular instrument hanging from his fingers, which is superscribed "Astrolabium".' (Catalogue by W.H. Black, p. 214)