Journeys over Land and Sea
* * * * * * * * *
Journeys over Land and Sea Journeys of the Mind Journeys of the Imagination

Journeys Over Land and Sea: Astronomy and Navigation

Advances in astronomy and navigation stimulated exploration and new discoveries by enabling seafarers to steer by the stars and leave the coastline for the open ocean.


James Bassantin (1504?-1568)
Astronomia (Astronomy)
Lyon: Jean de Tournes, 1599.
Gift of the Burndy Library

Astronomia Printed paper instruments called volvelles provided astronomers with the positions of the Sun, Moon, and planets, freeing them from performing lengthy calculations derived from planetary tables. Bassantinís work, a general overview of astronomy, partly copies Petrus Apianusís Astronomicum Cśsareum of 1540. The Irish astronomer William Molyneux (1656-1698) once owned this copy.

View enlarged images from this item:


William Gilbert (1504?-1603)
De magnete, magneticisque corporibus, et de magno magnete tellure . . . (On the magnet, magnetic bodies, and the great magnet of the Earth . . .)
London: P. Short, 1600.
Gift of the Burndy Library

De magnete, magneticisque corporibus, et de magno magnete tellure . . . Although the magnetic lodestone had been used since ancient Greek times, Gilbertís work contains the first experimental research on the properties of magnetism. Gilbert argued, correctly, that the Earth is a natural magnet and that the Earthís magnetic poles are relatively near its geographic poles. As a result, mariners were better able to use the lodestone as an effective navigational tool.

View enlarged images from this item:


Alfonso X, King of Castile and Leon (1221-1284)
Tabule astronomice (Astronomical tables)
Venice: Johannes Hamman, 1492.
Gift of the Burndy Library

Tabule astronomice Navigators for Columbus would have taken the Alfonsine tables, a set of astronomical tables, on their expeditions to the New World. Once thought to have been devised by astronomers at the court of Alfonso X, the tables were extremely useful to navigators and crucial to early explorers. Because the tables considerably simplified astronomical calculations, the user could determine planetary positions without having to work with the underlying mathematical models that described the Ptolemaic solar system.

View enlarged images from this item:


Journeys over Land and Sea Journeys of the Mind Journeys of the Imagination
* * * * * * * * *
Smithsonian Institution Libraries Home