Februaky 2i\, 1910] 



NA TURE 



499 



Messrs. Macmillan and Co., Ltd., have published the 

 mathematical papers for admission into the Royal Military 

 Academy and the Royal Military College for the years 

 igoo-g in a single volume, the price of which is 6s. The 

 book has been edited by Messrs. E. J. Brooksmith and 

 R. M. Milne, who have supplied answers to the questions. 



A SECOND edition of "Acetylene: the Principles of its 

 Generation and Use," by Messrs. F. H. Leeds and \V. J. 

 Atkinson Butterfield, has been published by Messrs. Charles 

 GrifBn and Co., Ltd. The original issue of the work was 

 reviewed fully in Nature of December 10, 1903 (vol. Ixi.x., 

 p. 122), and it will suffice to say that the book has been 

 revised and enlarged, an appendi.^ including descriptions of 

 representative acetylene generators having been added. 



The second part of " A Catalogue of Books on Natural 

 History " has been issued by Mr. Bernard Quaritch, of 

 Grafton Street, London, W. The present part completes 

 the general works, and this section includes scientific 

 voyages and transactions of learned societies ; and the 

 works on zoology are also begun. We notice that the 

 section of the catalogue concerned with entomology includes 

 two important libraries brought together by authorities on 

 the subject. It is expected that the catalogue will be 

 completed in ten parts. 



The St. Catherine Press, Ltd., has published a handbook 

 to the Scandinavian winter health resorts, written by Dr. 

 T. N. Kelynack. The substance of the book originally 

 appeared as a series of articles in the Lancet. The descrip- 

 tions of places are written in a bright, interesting style, and 

 indicate that Dr. Kelynack speaks from personal knowledge 

 derived from direct inquiry and observation. Numerous 

 illustrations add greatly to the attractiveness of the guide, 

 which altogether should prove of value both to physicians 

 and patients and to holiday seekers. The price of the 

 book is IS. net. 



OUR ASTRONOMICAL COLUMN. 



Discovery of a New Comet, 19106. — A telegram from 

 the Kiel Centralstelle announces the discovery of a new 

 comet by M. Pidou.x at the Geneva Observatory. The 

 position of the comet on February 20, at yh. lom. (Geneva 

 M.T.), was R.A.=oh. 46m. 22-is., dec. =+7° 50' 41", 

 and the daily motion was —2-4 m. in R.A. and —24' in 

 declination. 



This position is in the constellation Pisces, the comet at 

 the time of discovery being slightly east of north from 5, 

 and a little north of west from €, Piscium. Reference to 

 the ephemeris for Halley's comet will show that, when 

 discovered, this new object was apparently less than 15° 

 away from Halley's. 



Comet iqioa. — The story of the discovery of comet 1910a 

 is now exactly recorded, by Mr. Innes, in No. 4387 of the 

 Astronomische Nachrichten (p. 311, February 12). It 

 appears that the first intimation received by Mr. Innes 

 arrived by a telephone message on January 15 from the 

 Leader, a Johannesburg newspaper. This message stated 

 that " Halley's comet was seen by Foreman Bourke, Driver 

 Tricker and Guard Marais at 4h. 45m. rising in front of 

 the sun. It was visible for about twenty minutes." 



The next morning, .Sunday, Messrs. Innes and Worssell 

 kept watch, but clouds prevented an observation. The 

 morning of January 17 was also cloudy, but there was a 

 break just above the place of sunrise, and the comet was 

 seen, at 5h. 29m. (standard time), by both observers in- 

 dependently, but by Mr. Worssell a few seconds the earlier ; 

 the telegram to Kiel was then dispatched. 



Mr. Innes asks that, if seen bv no one else earlier, it 

 may be placed on record that this comet was first seen 

 bv railwav officials at Kopjes, Orange Free State. 



In the same number of the Astronomische Nachrichten 

 NO. 2104, VOL. 82] 



Dr. Kobold gives the daily ephemeris, based on the 

 improved elements, extended to March 12 ; the following 

 is an extract : — 



Ephemeris for i2h. (_Berlin M.T.). 

 0(19100) 5(1910-0) logr log A M.ig. 



T910 h. m. 



Feb. 24 ... 22 109 ... +11 55-6 ,.. 0-05563 ... 0-29959 ... S'4 

 28 ... 22 146 ... -I- 12 53 8 ... o-o86Si ... 0-31812 ... 5'6 

 Mar. 4 ... 22 i8-i ... +13 48-5 ... 0-11505 ... 0-33461 ... 5-8 

 8 ... 22 21-3 ... -I- 14 40-5 .. 0-14086 ... 034936 ... 6-0 

 12 ... 22 24 3 ... + 15 31 -0 ... 0-16463 ... 0-36238 ... 6-2 

 The magnitudes are based on the observation made by 

 Prof. Hartwig on January 27 that the magnitude was 

 then about 20, and by calculation the magnitude at peri- 

 helion becomes about — 1-4. Observations made at Arcetri 

 on February 7 gave corrections of -l-2s. and -I- 04' to the 

 ephemeris places. 



From this ephemeris we see that the comet is_ now 

 apparently travelling, very slowly and in a direction slightly 

 east of north, through Pegasus, and when it rises on the 

 morning of March 3 it will be about 100' north of 

 31 Pegasi, a fifth-magnitude star; but observations will 

 be difficult owing to the apparent proximity of the sun. 



The ephemeris also shows that the comet is retreating 

 from the earth and sun at the rate of about two million 

 miles per day, approximately in the direction of the earth- 

 sun line; the present distances (February 24) are about 185 

 and 106 million miles respectively. 



In No. 7 of the Comptes rendus (February 14, p. 369) 

 M. E. Esclangon describes some remarkable transforma- 

 tions which he observed to take place in comet 1910a 

 between Januarv 22 and 30. On the former date the 

 nucleus was about 15" in diameter and very bright, and 

 from each side of it, normally to the general direction of 

 the tail, there appeared two' currents of matter, nearly 

 rectilinear near the source, but curving rapidly at some 

 distance from it to form the tail. On January 30, how- 

 ever, the aspect was entirely changed, the nucleus being 

 only 3" or 4" in diameter, and very sharply defined. The 

 two currents of bright matter had been replaced by a 

 circular nebulositv eccentric in regard to the nucleus ; on 

 Februarv 9 no tail was visible. M. J. Comas Sola also 

 communicates a paper dealing with the form of the comet, 

 to which we hope to refer later. In a brief note M. 

 Borrelly reports that on February 7 the comet was very 

 faint, .-ippearing fainter than stars of the eighth magnitude; 

 on February 10 the magnitude was estimated as 8-5, and 

 the comet was nearly circular, with a diameter of 25'. 



Halley's Comet.— The following is a further extract 

 from Mr. Crommelin's ephemeris as published in No. 4379 

 of the Astronomische Nachrichten : — 



Ephemeris for Grcenivich noon. 

 ,0,0 R.A. Decl. log r log i 



h. m. . , 



March i ... o 34-0 

 6 ... o 30-2 

 II ... o 26-4 

 16 ... o 22-6 

 21 ... o 18 5 

 26 ... o 14-2 

 31 ... o 9-7 

 April 5 ... o 49 

 These positions will be found plotted on the chart we 

 gave in our issue of January 13 (No. 2098, p. 320), and 

 during the greater part of .^pril the comet will prob- 

 ably be unobservable. At present (February 24) the 

 distances of the comet from the sun and from the earth 

 are 116 and 175 million miles respectively, and the latter 

 is increasing; but during the first week in March the earth 

 and comet will again approach each other, until on 

 March 31 the distance separating them will be but about 

 158 million miles. 



In No. 419 of the Observatory (p. 105) Mr. Crommelin 

 directs attention to the following parallelism of the election 

 results of 1S35 and igio — both comet years — which is 

 sufficiently remarkable to quote here : — 



P.irliaments of ... i8q2 iqo6 iSq; 1910 



Liberals 514 ... 513 ... 3^5 •-- 396 



Opposiion 144 ... 157 •■• 273 ... 274 



