March 5, 1908J 



NATURE 



421 



Messrs. John J. Griffin and Sons, Ltd., have issued 

 an illustrated and descriptive catalogue of apparatus suit- 

 .ible for demonstration purposes in the teaching of physio- 

 ijfraphv, physiology, and hygiene. The information in- 

 iluded respecting globes and lantern-slides should bi- par- 

 ticularlv useful to teachers of geography who follow modern 

 methods of presenting their subject. 



A SF.COND edition of Prof. G. S. Boulger's " Wood : a 

 Manual of the Natural History and Industrial Applica- 

 tions of the Timbers of Commerce," has been published 

 by Mr. Edward Arnold. The first edition was reviewed 

 in Natire of January 15, 1903 (vol. l.Kvii., p. 245), and 

 it will bo sufficient here to say the worl-; has been revised 

 .ind enlarged, and th.it its price is now I2.«. 6rf. net. 



Tnt; National Home-Reading Union, with the coopera- 

 tion of the Library .Association, has arranged to publish 

 ,1 pennv monthly magazine for the guidance of readers in 

 public libraries in the choice of books and other reading. 

 The first issue, that for February, is now available, and 

 among its principal contents may be noticed articles by 

 Prof. H. H. Turner, F.R.S., on books about astronomy; 

 books about Australia, by Sir John Cockburn, K.C.M.G. ; 

 and the literature of the sea, by Mr. Frank T. BuUen. 

 The Reader's Review, as the guide is called, is intended 

 primarily for localisation in the various libraries by means 

 of the insertion of additional pages containing local literary 

 notes, lists of recent additions, and so on. The idea of 

 assisting readers in their choice of books is excellent, and 

 it is to be hoped that the efforts of the editorial board 

 will prove successful. The paper is published by Messrs. 

 Sherratt and Hughes. 



OUR ASTROXOMICAL COLUMN. 



ASTRONO.MICAL OCCURREN'CES IN MARCH : — 

 March 5. ih. Venus in conjunction with Moon. Venus 

 5° 49' N. 

 ,, 8h. 59m. Minimum of Algol (/8 Per.sei). 

 6. 3h. Mars in conjunction with Moon. Mars 



5" 26' N. 

 S. loh. lom. to loh. 32m. Moon occults 6- Tauri 



(Mag. 4-2). 

 9. iih. 42111. 10 i6h. 31m. Transit of Jupiter's Satel- 

 lite IV. (Callisto). 

 10. Pallas (Mag. 8^04) in opposition to the Sun. 

 12. 6h. I2ni. to gh. S4m. Transit of Jupiter's SateUite 



III. (Ganymede). 

 IV 4h. Jupiter in conjunction with Moon. Jupiter 

 i°7'S. 



19. 9h. 47ni. to I3h. 2Sm. Transit of Jupiter's Satellite 



III. (Ganymede). 



20. I2h. Sun enters Aries, Spring commences. 



21. Venus. Illuminated portion of disc = o'677. 



26. 22h. Mercury at maximum elongation West 



(27° 49')- 

 28. 7h. 30m. Minimum of Algol {B Persei). 

 31. Ceres (Mag. 7°'36) in opposition to the Sun. 



MiLKO.METER OnsERV.vTiONS OF Phceiie. — During the 

 period July 24 to October 16, 1906, Prof. Barnard made a 

 number of observations of Phoebe, Saturn's tenth satellite, 

 of which he now publishes the results in No. 4234 of the 

 Astnynoiiiische Xachrichten (p. 145, February 22). .\ 

 variation of brightness, amounting to half a magnitude 

 or more, is indicated by the fact that while the object was 

 usually a difficult one, of magnitude i6-o or 16-5, it was 

 found to be comparatively easy during October, and was 

 perhaps brighter than the sixteenth magnitude. On several 

 iii'ca-iiins the satellite presented a hazy appearance, and 

 Prof, Barnard suggests that, should future observations 



NO. 2001, VOL. 77] 



confirm this nebulous or cometary character, the solution 

 of the question of Phcebe's origin' in the Saturnian system 

 will be simplified. 



Epiiemeris for Daniel's Comet, i907d. — The following 

 is an extract from Herr Kritzinger's ephemeris for 

 comet 1907^, published in No. 4234 (p. 159, February 22) 

 of the Astrononiische Xachrichlen : — 



Ephemeris 12/1. (Berlin M.T.). 

 1(1908-0) 8(1908-0) 190S 0(19080) 



a(i9oS-o> 



Mar. 5 . 

 .. 13 



15 4-4 ... 

 14 59 7 •• 



-6 44 o Mar. 21 ... 14 53-6 ... - 5 6-9 

 -5 57'o! „ 29 ... 1446-5 ... -4 15-5 



The computed magnitude of this object is io-6, and the 

 comet is now apparently travelling eastwards through the 

 constellation Libra towards Virgo, rising a little south of 

 cast at about 10.30 p.m. On March 17 it will be about 

 23° north of S Librae. 



The Spectrum of the Aurora Borealis. — An exhaustive 

 summary and discussion of the results hitherto obtained 

 from spectroscopic observations of the aurora appears in 

 No. 9, vol. x.xxv. (September, 1907), of the Monthly 

 Weather Revieu' (U.S. Weather Bureau), from the pen of 

 Dr. W. Marshall Watts. All the recorded visual and photo- 

 graphic observations made since the time of Angstrom's 

 observations in 1867 are analysed and compared, and the 

 iTiost probable values for the wave-lengths of the principal 

 lines are tabulated ; for the chief green line this value is 

 5571-6, and for the red line 6303-4. Various observations 

 suggest that the spectrum varies at different times, and 

 Dr. Watts urges that far more numerous and continuous 

 observations should be made. With the apparatus which 

 he describes, such observations could be made at a very 

 small cost by any qualified observer. 



Sun-spot Spectra. — No. i, vol. xxvii., of the Astro- 

 physical Journal (January) contains two papers which 

 should prove of interest to all workers in solar physics. 

 The first of these is by Prof. W. S. Adams, and really 

 consists of a preliminary catalogue of lines affected in sun- 

 spots. The photographs on which these lines were detected 

 were taken with a Littrow spectrograph, used in conjunc- 

 tion with the Snow telescope of the Mount Wilson Solar 

 Observatory, and give a linear dispersion of i mm. = 1-5 A 

 The present catalogue includes a list of the lines affected 

 in sun-spots in the region A 4000 to X 4500, and is to be 

 followed by other lists giving the results obtained in other 

 parts of the spectrum. The lines, their behaviour, and 

 their origins are not discussed now, the discussion being 

 reserved until the catalogue is complete ; the present list 

 includes nearly 900 lines, for each of which the probable 

 origin, the intensities in Rowland's table and in the spot, 

 together with remarks on its behaviour in the spot, are 

 given. 



In the second paper Mr. Charles M. Olmsted, of the 

 Mount Wilson Observatory, announces that he has 

 succeeded in identifying certain bands in the sun-spot spec- 

 trum with similar bands in the spectrum of the calcium 

 arc burning in an atmosphere of hydrogen. There are two- 

 main groups of these bands, the stronger one at \ 6385, 

 the weaker running through the B group, and the com- 

 parison with the spot spectrum leaves no doubt as to their 

 identity. 



.\sTRONOMV IN Wales.— The Cambrian Natural Observer 

 (January) contains several papers on astronomical subjects- 

 read before the Astronomical Society of Wales last year. 

 .\mong others mav be mentioned a paper by Mr. T. E. 

 Heath on star clouds and nebula;, another dealing with 

 transits past and present, and an abstract of a paper 

 by the Rev. John Griffith on the astronomy of the 

 stones, delivered in November la'st before a crowded 

 meeting of the Cardiff Archasological Society and the 

 Astronomical Society in Wales. Sir Norman Lockyer's 

 method of investigation of stone monuments was explained, 

 and the audience was urged to aid in the accumulation of 

 the orientation data which is apparently so abundant in 

 Wales. 



The periodical is again to be issued as a quarterly. 



