Baldwin & Sons
Auction 108 8 Nov 2022
View prices realized
► Sale information
Find similar lots
France, Second Empire, Analysis of Solar Prominences by Jannsen in 1868 through the Eclipse of the Sun. Bronze plaque 1874 in an oaken frame, (315mm. including frame), a larger cast bronze after the reverse of the smaller French struck medal commemorating both Janssen's and Lokyer's discovery of helium and study of solar protuberances. (Medal : Divo.583, Coll.1954). Half-naked, cloaked Phoebus, standing, driving a chariot pulled by four horses, raising his right arm to the sun which is covered by protuberances and either side the zodiac signs for Leo and Virgo, in French 'ANALYSIS OF SOLAR PROTUBERANCES. AUGUST 18, 1868'. Signed ALPHÉE DUBOIS 1874. Extremely Fine, dark bronze toning, small split in oak frame.
Pierre Jules César Janssen, (22 Feb.1824 – 23 Dec.1907), French astronomer who in 1868 discovered the chemical element helium and how to observe solar prominences without an eclipse. His work was independent of that of the Englishman Sir Joseph Norman Lockyer, who made the same discoveries at about the same time.
While observing a solar eclipse in Guntur, India, on August 18, 1868, Janssen noted that the spectral lines in the solar prominences were so bright that they should be easily observable in daylight. The next day he used his spectroscope to study the solar prominences. That enabled many more such observations to be made than previously, when such phenomena had been observable only for the few minutes' duration of solar eclipses. During his observations he also noted a yellow spectral line near, but distinct from, the prominent lines of sodium. That line was from helium, which was not observed on Earth until 1895.
Pierre Jules César Janssen, (22 Feb.1824 – 23 Dec.1907), French astronomer who in 1868 discovered the chemical element helium and how to observe solar prominences without an eclipse. His work was independent of that of the Englishman Sir Joseph Norman Lockyer, who made the same discoveries at about the same time.
While observing a solar eclipse in Guntur, India, on August 18, 1868, Janssen noted that the spectral lines in the solar prominences were so bright that they should be easily observable in daylight. The next day he used his spectroscope to study the solar prominences. That enabled many more such observations to be made than previously, when such phenomena had been observable only for the few minutes' duration of solar eclipses. During his observations he also noted a yellow spectral line near, but distinct from, the prominent lines of sodium. That line was from helium, which was not observed on Earth until 1895.