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 latitude 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 Association.
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 Cluster (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 Gi