1890 Schiaparelli finds for Venus an identical period of rotation and revolution.

1890 Publication of Thollon's map of the solar spectrum.

1890 Bigelow's mathematical theory of coronal structures.

1890 Foundation of the British Astronomical a.s.sociation.

1890 Measurements by Keeler at Lick of nebular radial movements.

1890 Janssen's ascent of Mont Blanc, by which he ascertained the purely terrestrial origin of the oxygen-absorption in the solar spectrum.

1890 Newcomb's discussion of the transits of Venus of 1761 and 1769.

1890 Spiral structure of Magellanic Clouds displayed in photographs taken by H. C. Russell of Sydney.

1890 Publication of the Draper Catalogue of Stellar Spectra.

1890, April 24 Spica announced by Vogel to be a spectroscopic binary.

1890, June Gore's Catalogue of computed Binaries.

1890, November Study by Sir William and Lady Huggins of the spectra of Wolf and Rayet's stars in Cygnus.

1890, November Discovery by Barnard of a close nebulous companion to Merope in the Pleiades.

1890, November McClean Spectrographs of the High and Low Sun.

1891 Capture-theory of comets developed by Callandreau, Tisserand, and Newton.

1891 Duner's spectroscopic researches on the sun's rotation.

1891 Preponderance of Sirian stars in the Milky Way concluded by Pickering, Gill, and Kapteyn.

1891 Detection by Mrs. Fleming of spectral variations corresponding to light-changes in Beta Lyrae.

1891 Establishment of the Harvard College Station at Arequipa in Peru (height 8,000 feet).

1891 Variations of lat.i.tude investigated by Chandler.

1891 Prominence-photography set on foot by Hale at Chicago and Deslandres at Paris.

1891 Schmidt's Theory of Refraction in the Sun.

1891, April Meeting at Paris of the Permanent Committee for the Photographic Charting of the Heavens.

1891, May 9 Transit of Mercury.

1891, Aug. 19 Presidential Address by Huggins at the Cardiff Meeting of the British a.s.sociation.

1891, Dec. 10 Nova Aurigae photographed at Harvard College.

1891, Dec. 20 Photographic maximum of Nova Aurigae.

1891, Dec. 22 First photographic discovery of a minor planet by Max Wolf at Heidelberg.

1892 Commencement of international photographic charting work.

1892 Photographic determination by Scheiner of 833 stars in the Hercules Cl.u.s.ter (M 13).

1892 Publication of Vogel's spectrographic determinations for fifty-one stars.

1892 Publication of Pritchard's photographic parallaxes.

1892, Jan. 2 Death of Sir George Airy.

1892, Jan. 21 Death of Professor Adams.

1892, Feb. 1 Announcement by Anderson of the outburst of a new star in Auriga.

1892, Feb. 5 Appearance of the largest sun-spot ever photographed at Greenwich.

1892, March Photograph of Argo nebula taken by Gill in twelve hours.

1892, March 6 Discovery of a bright comet by Swift.

1892, June 29 Death of Admiral Mouchez. Succeeded by Tisserand as director of the National Observatory, Paris.

1892, Aug. 4 Favourable Opposition of Mars.

1892, Aug. 17 Rediscovery at Lick of Nova Aurigae.

1892, Sept. 9 Discovery by Barnard of Jupiter's inner satellite.

1892, Oct. 12 First photographic discovery of a comet by Barnard.

1892, Nov. 6 Discovery of Holmes's comet.

1892, Nov. 23 Shower of Andromede meteors visible in America.

1892 Poynting's Determination of the Earth's Mean Density.

1892 Duner's Investigation of the System of upsilon Cygni.

1892 Photographic investigation by Deslandres of the spectra of prominences.

1892 Photographs of the sun with faculae and chromospheric surroundings taken by Hale with a single exposure.

1892 Investigation by T. J. J. See of the ancient colour of Sirius.

1892 Publication of T. J. J. See's Thesis on the Evolution of Binary Systems.

1892 Chandler's theory of Algol's inequalities.

1892 Nebula in Cygnus photographically discovered by Max Wolf.

1893, Jan. 28 Kapteyn's investigation of the structure of the stellar universe.

1893, March 10 Gill announces his results from the Opposition of Victoria, among them a solar parallax = 8.809".

1893, April 16 Total solar eclipse observed in South America and West Africa.

1893 Publication of Kruger's _Catalog der Farbigen Sterne_.

1893 Conclusion of Boys's series of Experiments on the Density of the Earth.

1893 Publication of _Cordoba Durchmusterung_, vol. i.

1893 Fabry shows comets to be dependents of the Solar System.

1893 Publication of Easton's _Voie Lactee_.

1893 Campbell detects bright H Alpha in Gamma Argus and Alcyone.

1893 Nova Normae photographed July 10; discovered on plates, October 26.

1893, May 28 Death of Professor Pritchard.

1893, July 27 Installation of 28-inch refractor at the Royal Observatory, Greenwich.

1893, December Exterior nebulosities of Pleiades photographed by Barnard.

1893, Dec. 6 Death of Rudolf Wolf.

1894, January Sun-spot maximum.

1894 Publication of Potsdam _Photometric Durchmusterung_, part i.

1894 Publication of Roberts's _Celestial Photographs_, vol. i.

1894 Wilson and Gray's determination of the sun's temperature.

1894 Barnard's micrometric measures of asteroids.

1894 McClean's gift of an astrophysical outfit to the Cape Observatory.

1894 Establishment of the Lowell Observatory at Flagstaff, Arizona.

1894 Taylor's triple achromatic objective described.

1894, April 3 Discovery of Gale's Comet.

1894 Sampson's investigation of the sun's rotation.

1894, Oct. 20 Favourable opposition of Mars.

1894, Nov. 11 Transit of Mercury.

1894, December Howlett impugns the Wilsonian theory of sun-spots.

1894, Dec. 14 Death of A. Cowper Ranyard.

1895 Publication of Newcomb's _Astronomical Constants_.

1895 Bailey's Photometric Catalogue of 7,922 Southern Stars.

1895 Bailey's photographic discovery of variable star cl.u.s.ters.

1895 Publication of E. W. Brown's _Lunar Theory_.

1895 Tisserand's theory of the inequalities of Algol.

1895 Stratonoff's determination of the sun's rotation from photographs of faculae.

1895 Binary character of Eta Aquilae spectroscopically recognised by Belopolsky.

1895 Presentation of the Crossley reflector to the Lick Observatory.

1895, March 23 Great nebula in Ophiuchus discovered photographically by Barnard.

1895, March 25 Ramsay's capture of Helium.

1895, April Const.i.tution of Saturn's rings spectrographically demonstrated by Keeler.

1895 Binary character of Delta Cephei spectroscopically detected by Belopolsky.

1895, June 11 Death of Daniel Kirkwood.

1895, July 7 Death of F. W. G. Sporer.

1895, October Nova Carinae spectrographically discovered by Mrs. Fleming.

1895, Dec. 12 Nova Centauri spectrographically discovered by Mrs. Fleming.

1895, Dec. 28 Death of John Russell Hind.

1896 Gill's Report on the Geodetic Survey of South Africa.

1896 Appearance of Loewy's Photographic Atlas of the Moon, part i.