December 7, 1899] 



NATURE 



^11 



OUR ASTRONOMICAL COLUMN. 

 Astronomical Occurrences in December :— 



December 9. I2h. 14111. Minimum of Algol (;8 Persei). 



10-12. Epoch of Geminid meteoric shower (radiant 



106° + 33"). 

 12. gh. 3m. Minimum of Algol (j8 Persei). 

 15. 2h. 48m. to 3h. 34m. Occultation of the star 



K- Tauri (mag. 5 "5) by the moon. 

 15. 2h. 55m. to 3h. 27m. Occultation of the star 



t^ Tauri (mag. 46) by the moon. 

 1$. Sh. 52m. Minimum of Algol (3 Persei). 

 15. Venus. Illuminated portion of disc = 0"928. 



15. Mars. Illuminated portion of disc = o"9q8. 



16. Partial eclipse of the moon. 



ilh. 45m. First contact with shadow. 

 I3h. 26h. Middle of the eclipse. 

 I5h. 7m. Last contact with shadow. 

 Magnitude of the eclipse = 0995. 



16. ish. 3601. to i6h. iim. Occultation of Neptune 



by the moon. 



17. 5h. Neptune in opposition to the sun. 



18. i8h. 31m. to I9h. 9m. Occultation of / Gemi- 



norum (mag. 5 "2) by the moon. 



20. Jupiter 9° W. of Mercury, on Dec. 24, 11°, and 



on Dec. 27, 14°. 



21. Saturn. Outer minor axis outer ring = 1 5" 76. 



21. i8h. 4m. Transit of Jupiter's Sat. III. Egress. 



22. I7h. Mercury in conjunction with Uranus 



(Mercury 2° 17' N.). 

 25. ih. Mercury at greatest elongation (22° 5' W.). 



25. I4h. 39m. to I5h. 47m. Occultation of the star 



D.M. - 10°, 3570 (mag. 6) by the moon. 



26. i6h. 22m. to I7h. 3m. Occultation of the star 



83 Virginis (mag. 5-8) by the moon. 



29. 7 a.m. Jupiter, 6° E. of the moon. 



30. ,, ,, 8'' W.N. W. of the moon. 



31. ,, Mercury, 5° W.N. W. of the moon. 



The red spot on Jupiter will be about central on Dec. 21, 

 7.44 a.m. ; Dec. 26, 6.54 a.m., and Dec. 28, 8.33 a.m. 



Mercury and Jupiter as Morning Stars.— In the dark 

 mornings of December it is almost as convenient for amateurs to 

 eflfect observations of celestial objects as it is in the evening 

 hours. It may therefore be of interest to mention that at about 

 Christmas time Mercury and Jupiter will be favourably visible 

 above the S.E. horizon just before sunrise, and that the crescent 

 of the moon will be placed near these planets on the last 4hree 

 mornings of 1899. The following are the times of rising of 

 Jupiter, Mercury and the sun on thirteen days : — 



Dec. 



Holmes' Comet (1899 </). 



Ephemeris for i zh. Greenwich Mean Time. 



Dec. 



NO. I 57 I, VOL. 61] 



Spectru.m of p. Cygnl— Herr A. Belopolsky has recently 

 obtained several photographs of the spectrum of the variable 

 star P Cygni (mag. 5), and states the results of his measure- 

 ments in the Astronoinische Nachrichten (Bd. 150, No. 3603). 

 The instrument used was the two-prism spectrograph (camera 

 25 cm. long) attached to the 30-inch refractor of the Pulkowa 

 Observatory. Both bright and dark lines are given, and it is 

 noted that while the bright lines generally occupy a normal 

 position, the dark lines are displaced towards the violet or more 

 refrangible end of the spectrum. It is also interesting to note 

 that several of the lines found are ascribed to nitrogen. The 

 following table gives the wave-lengths of the lines in the star's 

 spectrum with their probable origins : — 



ANNIVERSARY MEETING OF THE ROYAL 

 SOCIETY. 



"pOLLOWING the usual custom, the anniversary meeting of 

 ^ the Royal Society was held in the apartments of the 

 Society at Burlington House on St. Andrew's Day, November 

 30. The auditors of the Treasurer's accounts read their report, 

 and the Secretary read the list of Fellows elected and deceased 

 since the last anniversary. The President, in his anniversary 

 address, referred to M. Haffkine's experience and views regarding 

 preventive inoculation, and then proceeded to the award of the 

 medals. 



Copley Medal. 



The Copley Medal is conferred upon Lord Rayleigh for his 

 splendid services to Physics. 



Lord Rayleigh's investigations have increased our knowledge 

 of almost every department of physical science, covering the 

 experimental as well as the mathematical parts of the subject. 

 Acoustics, optics, electricity, and magnetism, the molecular 

 theory of the constitution of bodies, the theory of elasticity, the 

 composition of the atmosphere, are but a selection from the sub- 

 jects of his investigations. In acoustics he has added to our 

 knowledge of resonance (the subject of his first paper in the 

 Philosophical Transactions), the behaviour of singing flames, 

 the vibrations of jets, the general theory of the vibrations of 

 dynamical systems, while his masterly ""Theory of Sound" has 

 thrown light on and given unity to the whole of the subject. 

 In optics, his researches include the theory of the scattering of 

 light by small particles, with its application to the explanation 

 of the blue of the sky, anomalous dispersion, the nature of white 

 light, reflection from crystals, and the general theory of optical 

 instruments. In electricity and magnetism, in addition to 

 theoretical investigations of great importance on the distribution 



