Part 64 (2/2)

1840, March 2 Death of Olbers.

1840 First attempt to photograph the moon by J. W. Draper.

1842 Doppler enounces principle of colour-change by motion.

1842 Conclusion of Baily's experiments in weighing the Earth.

1842, July 8 Total solar eclipse. Corona and prominences observed by Airy, Baily, Arago, and Struve.

1843, Feb. 27 Perihelion-pa.s.sage of great comet.

1845, February Completion of Parsonstown reflector.

1845, April Discovery with it of spiral nebulae.

1845, April 2 Daguerreotype of the sun taken by Foucault and Fizeau.

1845, Oct. 21 Place of Neptune a.s.signed by Adams.

1845, Dec. 8 Discovery of Astraea by Hencke.

1845, Dec. 29 Duplication of Biela's comet observed at Yale College.

1846 Melloni's detection of heating effects from moonlight.

1846, March 17 Death of Bessel.

1846, Sept. 23 Discovery of Neptune by Galle.

1846, Oct. 10 Neptune's satellite discovered by La.s.sell.

1847 Publication of Sir J. Herschel's _Results of Observations at the Cape of Good Hope_.

1847 Cyclonic theory of sun-spots stated by him.

1848 J. R. Mayer's meteoric hypothesis of solar conservation.

1848 Motion-displacements of Fraunhofer lines adverted to by Fizeau.

1848, April 27 New Star in Ophiuchus observed by Hind.

1848, Sept. 19 Simultaneous discovery of Hyperion by Bond and La.s.sell.

1849 First experimental determination of the velocity of light (Fizeau).

1850, July 17 Vega photographed at Harvard College.

1850, Nov. 15 Discovery by Bond of Saturn's dusky ring.

1851 O. Struve's first measurements of Saturn's ring-system 1851, July 28 Total solar eclipse observed in Sweden.

1851, Oct. 24 Discovery by La.s.sell of two inner Uranian satellites.

1851 Schwabe's discovery of sun-spot periodicity published by Humboldt.

1852, May 6 Coincidence of magnetic and sun-spot periods announced by Sabine.

1852, Oct. 11 Variable nebula in Taurus discovered by Hind.

1852 La.s.sell's two-foot reflector transported to Malta.

1853 Adams shows Laplace's explanation of the moon's acceleration to be incomplete.

1854 Hansen infers from lunar theory a reduced value for the distance of the sun.

1854 Helmholtz's ”gravitation theory” of solar energy.

1856 Piazzi Smyth's observations on the Peak of Teneriffe.

1857 Saturn's rings shown by Clerk Maxwell to be of meteoric formation.

1857, April 27 Double-star photography initiated at Harvard College.

1858 Solar photography begun at Kew.

1858, Sept. 30 Perihelion of Donati's comet.

1859 Spectrum a.n.a.lysis established by Kirchhoff and Bunsen.

1859 Carrington's discovery of the compound nature of the sun's rotation.

1859, Sept. 1 Luminous solar outburst and magnetic storm.

1859, Oct. 19 Merope nebula discovered by Tempel.

1859, Dec. 15 Chemical const.i.tution of the sun described by Kirchhoff.

1860, Feb. 27 Discovery by Liais of a ”double comet.”

1860, May 21 New star in Scorpio detected by Auwers.

1860, July 18 Total solar eclipse observed in Spain. Prominences shown by photography to be solar appendages.

1861, June 30 The earth involved in the tail of a great comet.

1861-1862 Kirchhoff's map of the solar spectrum.

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