- Galileo Galilei (1564–1642) hoped to use the movements of four large moons of the planet Jupiter to determine longitude at sea, and applied, without success, to the Spanish crown for the prize offered for this achievement.
- This instrument, known as the Giovilabio, is based on Galileo's ideas. The larger revolving disc represents Jupiter and the smaller one the Sun. The discs are connected and their movements show when the four moons, observed from the Earth, enter and leave the shadow of Jupiter. The instrument’s plate is engraved in Latin with tables to predict these eclipses and it can also indicate time (though less precisely) from the observed positions of the moons.
- The donor of this Giovilabio believed that it had been made under the direct supervision of Gaileo, by one of his pupils. We now think it was at the Museo di Antichi Stumenti in Florence, circa 1900.
- 1. Bedini, Silvio A. “The Galilean Jovilabe,“ Nuncius, 1, 1986, pp. 25-46.
- 2. Bedini , Silvio A. The Pulse of Time: Galileo, the Determination of Longitude, and the Pendulum Clock, Florence: Leo S. Olschki, 1991, pp. 7-21.
- 3. G. Vanpaemel, "Science Disdained: Galileo and the Problem of Longitude," Italian Scientists in the Low Countries in the XVIIth and XVIIIth Centuries, Edited by C. S. Maffeoli and L. C. Palm, Amsterdam: Rodopi, 1989, pp. 111-129.
- 4. The Jovilabe: History and Design. http://hotgates.stanford.edu/Eyes/Jovilabe.old/jovhistory.html, accessed March 31, 2013.
- Currently not on view
- Object Name
- Galilaean Giovilabio (replica)
- Physical Description
- brass (overall material)
- overall: 8 cm x 20 cm x 41 cm; 3 5/32 in x 7 7/8 in x 16 5/32 in
- ID Number
- catalog number
- accession number
- Credit Line
- Carolyn Mugar
- See more items in
- Medicine and Science: Physical Sciences
- Time and Navigation
- Measuring & Mapping
- Data Source
- National Museum of American History
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