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SEVENTEENTH CENTURY FRENCH JESUIT LONGITUDE DETERMINATIONS IN ASIA: ON THE ART OF RECTIFYING THE CLOCKS
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On 18 February 1679 Paris Observatory astronomer Jean Dominique Cassini presented a new map of the Moon to the Academy of Sciences in Paris, and this then became the standard reference work for French astronomers who carried out selenographical observations. Among these was a contingent of Jesuit missionary-astronomers who sailed from Brest on 3 March 1685, bound for China. En route they were forced to spend some months in Siam (present-day Thailand) and used the map when they observed the lunar eclipse of 11 December 1685. In this paper we examine the creation of the 1679 Moon map and its use by the French Jesuit missionary-astronomers in Siam in 1685.
The methods and quality of seventeenth century timings of immersions and emersions of the Galilean satellite Io were studied. It was found that the quality of the observations was very good but that in the cases where these observations were used for longitude determinations, the results were impaired by the inaccuracy of Cassini's ephemerides that were used.
The first great ruler to encourage the adoption of Western culture and technology throughout Siam (present-day Thailand) was King Narai, who also had a passion for astronomy. He showed this by encouraging French and other Jesuit missionaries, some with astronomical interests and training, to settle in Siam from the early 1660s. One of these was Father Antoine Thomas, and he was the first European known to have carried out scientific astronomical observations from Siam when he determined the latitude of Ayutthaya in 1681 and the following year observed the total lunar eclipse of 22 February. A later lunar eclipse also has an important place in the history of Thai astronomy. In 1685 a delegation of French missionary-astronomers settled in Ayutthaya, and on 10 –11 December 1685 they joined King Narai and his court astrologers and observed a lunar eclipse from the King's ‗country retreat' near Lop Buri. This event so impressed the King that he approved the erection of a large modern well-equipped astronomical observatory at Lop Buri. Construction of Wat San Paulo Observatory—as it was known—began in 1686 and was completed in 1687. In this paper we examine these two lunar eclipses and their association with the development of scientific astronomy in Siam.
The Quest for Longitude
- W J H Andrews
Andrews, W.J.H., 1996. The Quest for Longitude: The Proceedings of the Longitude Symposium... Cambridge
(Mass.), Harvard University Press.
Relation de l'Ambassade de Mr. le Chevalier de Chaumont a la cour du Roy de Siam, Avec ce qui s'est Passé de Plus Remarquable Durant son Voyage
- A De Chaumont
de Chaumont, A., 1733. Relation de l'Ambassade de Mr. le Chevalier de Chaumont a la cour du Roy de Siam,
Avec ce qui s'est Passé de Plus Remarquable Durant son Voyage. La Haye, Isaac Beauregard (in French).
Voyage de Siam fait par M. L'Abbé de Choicy
- , F.-T De Choicy
de Choicy, F.-T., 1741. Voyage de Siam fait par M. L'Abbé de Choicy. Trevoux, La Compagnie (in French).
Voyage de Siam des Pères Jesuites, Envoyes par le Roy aux Indes & à la Chine. Avec leurs Observations Astronomiques, et leurs Remarques de Physique, de Géographie, d'Hydrographie, & d'Histoire
- G Tachard
Tachard, G., 1686. Voyage de Siam des Pères Jesuites, Envoyes par le Roy aux Indes & à la Chine. Avec
leurs Observations Astronomiques, et leurs Remarques de Physique, de Géographie, d'Hydrographie, &
d'Histoire. Paris, Arnould Seneuze (in French).