Heraclides' system, ca. 1675
Oxford, Museum of the History of Science, inv. 57517

The device, the work of Domenico Santini, reproduces the system of Heraclides Ponticus (4th century B.C.): Venus and Mercury revolve around the Sun, while the other planets revolve around the Earth. Jupiter's four moons and Saturn's three reflect astronomy's most recent discoveries.