is section of International
Photographic Catalogue.
1901, Feb. 22 Nova Persei discovered by Anderson.
1901, February Variability of Eros announced by Oppolzer.
1901, April 23 Apparition of a great comet at the Cape.
1901 Publication of Pickering's _Photometric Durchmusterung_.
1901 Miss Cannon's discussion of the spectra of 1,122
Southern stars.
1901 Kapteyn's investigation of mean stellar parallax.
1901 Campbell's determination of the sun's velocity.
1901 Porter's research on the solar motion in space.
1901 Bigelow's magnetic theory of the solar corona.
1901 Hussey's measurements of the Pulkowa double stars.
1901 Radial velocities of the components of Delta Equulei
measured at Lick.
1901, April 16 Death of Henry A. Rowland.
1901, June Nebular spectrum derived from Nova Persei.
1901, Aug. 23 Nebula near Nova Persei photographed by Max Wolf.
1901, Sept. 20 The same exhibited in spiral form on a plate taken by
Ritchey at the Yerkes Observatory.
1901, Nov. 8 Photograph taken by Perrine with the Crossley
reflector showed nebula in course of rapid change.
1901, Sept. 19 Unveiling of the McClean "Victoria" telescope at the
Royal Observatory, Cape of Good Hope.
1901 Sun-spot minimum.

TABLE II.

CHEMICAL ELEMENTS IN THE SUN (ROWLAND, 1891).

Arranged according to the number of their representative Lines in the
Solar Spectrum.

Iron (2000+). Neodymium. Cadmium.
Nickel. Lanthanum. Rhodium.
Titanium. Yttrium. Erbium.
Manganese. Niobium. Zinc.
Chromium. Molybdenum. Copper (2).
Cobalt. Palladium. Silver (2).
Carbon (200+). Magnesium (20+). Glucinum (2).
Vanadium. Sodium (11). Germanium.
Zirconium. Silicon. Tin.
Cerium. Strontium. Lead (1).
Calcium (75+). Barium. Potassium (1).
Scandium. Aluminium (4).

_Doubtful Elements._--Iridium, osmium, platinum, ruthenium, tantalum,
thorium, tungst