Pierre Jules César Janssen
Pierre Jules César Janssen (22 February 1824 – 23 December 1907; went by both Pierre and Jules) was a French astronomer and balloonist. He presided over two international aeronautical conferences.
Janssen's work focused especially on the Sun. He with developing new methods of astronomical photography, and with initiating the discovery of helium with spectroscopy work during the eclipse of 1868.[1][2]
Janssen escaped the siege of Paris on 2 December 1870[3] and went on to be honorary president of the Société des aéronautes du siège de Paris.[4] During the escape he carried various instruments and developed an "aeronautical compass".[5]
In 1873 Janssen was made first chariman of the Société française de navigation aérienne.[6]
Janssen was made head of the observatory at Meudon in 1876.[1] This presumably gave him opportunities to interact with the military aeronautical researchers at Chalais-Meudon. He was responsible for the photographs taken of La France in 1884.[7]
In 1899, he led a team of scientists including Wilfrid de Fonvielle in a balloon expedition to photograph the Leonid meteor shower. The balloonists dropped a trail of postcards, stamped and addressed to the observatory, as a guide to reconstructing the balloon's route.[8]
He presided over the International Aeronautical Congress of 1889 and over its successor, the International Aeronautical Congress of 1900. His speech at the latter heralded the coming of a new civilization for the age of aeronautics.[9]
Publications by or about Pierre Jules César Janssen or Jules Janssen
- Sibillot, 1890, Gay-Lussac Aéronaute (Simple title: Gay-Lussac Aéronaute)
- Sibillot, 1890, Gay-Lussac Aéronaute (Simple title: Gay-Lussac Aéronaute)
- Janssen, 1895, Sur une ascension au sommet du Mont Blanc et les travaux exécutés (Simple title: On an ascent to the top of Mont Blanc and the work done, Journal: L'Aérophile)
- Fonvielle, 1906, J. Janssen (Simple title: J. Janssen, Journal: Wien. Luftsch. Zeit.)
- Publication 6546, 1908, Pierre Jules César Janssen (Simple title: Pierre Jules César Janssen, Journal: Wien. Luftsch. Zeit.)
- Armengaud jeune, 1909, Le Problème de l'Aviation (Simple title: Le Problème de l'Aviation, Deuxième édition.)
- Moore, 1921, Helium (Simple title: Helium, Journal: Jounral of the Franklin Institute)
Pierre Jules César Janssen (or Jules Janssen) participated in these events:
- International Aeronautical Congress of 1889 (Start date: 1889-07-31, Locations: Paris, Country: FR, Tech focus: • • )
- International Aeronautical Congress of 1900 (Start date: 1900-09-17, Locations: Paris • Institut de France, Country: FR, Tech focus: LTA • Balloon • Kite • Meteorology)
References
- ↑ 1.0 1.1 "Pierre Janssen", Encyclopedia Brittanica; last revised 24 July 2014.
- ↑ Moore, 1921, Helium, p. 145.
- ↑ Wise, 1873, Through the Air, p. 34. "The noted astronomer Janssen, who happened to be in Paris at the time of its investment by the Prussian army, preparing the necessary instruments for his observations to be made on the then approaching solar eclipse, would have been deprived of opportunities for conducting his experiments had it not been for the balloon facilities which he emergency of the war brought into play. The minister of public information furnished him the balloon 'La Volta,' of 72,000 cubic feet capacity, and a seaman as aëronaut; and on the morning of the 2d of December, 1870, and landed safely beyond the Prussian war lines at St. Nazaire the same day. He was thus enabled to view the eclipse in proper style on the 22d day of December following."
- ↑ Pocket-Book of Aeronautics, 1907, p. 443.
- ↑ Launay 2008, p. 53.
- ↑ Launay 2008, p. 57.
- ↑ Launay 2008, p. 58.
- ↑ Launay 2008, p. 59.
- ↑ Launay 2008, p. 60.
Bibliography
- Launay, Françoise. The Astronomer Jules Janssen: A Globetrotter of Celestial Physics. Translated by Storm Dunlop. Springer, 2008. ISBN 978-1-4614-0696-9.
Links
| Names | Pierre Jules César Janssen; Jules Janssen; Pierre Janssen |
|---|---|
| Birth date | 1824-02-22 |
| Death date | 1907-12-23 |
| Countries | FR |
| Locations | Paris; Meudon |
| Occupations | physicist, astronomer |
| Tech areas | Helium, Photography |
| Affiliations | |
| Wikidata id | Q298581 |
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