712 



NA TURE 



[November 25, 192: 



I 1 1 1 latest catalogue of second-hand books offered 

 for sale by Mr. F. Edwards, 83 High Street, Maryle- 

 bone, W.i, is No. 437 (November). It gives the 

 titles, and in many cases descriptions, of upwards of 

 800 volumes on oriental matters, mainly Chinese and 

 Japanese. 



The old-established firms of instrument-makers, 

 T. Cooke and Sons, Ltd., of London, York, and Cape 

 Town, and Troughton and Simms, Ltd., of London 

 and Charlton, have amalgamated, and the joint busi- 

 ness will be conducted under the name of Cooke, 

 Troughton and Simms, Ltd. 



We have received from Messrs. A. Gallenkamp and 

 Co., Ltd., of 19 and 2T Sun Street, Finsbury Square, 

 London, E.C.2, Part I. of the seventh edition of their 



catalogue of general chemical apparatus, including 

 balances and weights. In addition to the ordinary 

 requirements of the chemical laboratory, the catalogue 

 includes some special features such as Mellor's porosity 

 apparatus and a series of vacuum drying ovens. 



The " Collected Scientific Papers " by the late 

 Dr. John Aitken, the final sheets of which were 

 passed for press by Dr. C. G. Knott just before his 

 death, will shortly be published by the Cambridge Uni- 

 versity Press. The volume will contain a biographical 

 sketch of the author. " The Theory of Spectra and 

 Atomic Constitutions," by Prof. Niels Bohr, will also 

 be published by the Press in the near future. It 

 is based on lectures delivered in Cambridge and deals 

 with the application of the quantum theorv to prob- 

 lems of atomic structure. 



Our Astronomical Column. 



The Leonid Meteor Shower. — Mr. W. F. Denning 

 writes that " The nights of November 13 and 15 

 were alone suitable for observation at the period of 

 the Leonid display this year, and very few meteors 

 appeared. Mr. J. P. M. Prentice watched the heavens 

 on the night of November 15 between 5.45 and 12.45 

 and recorded only 44 meteors during the seven hours, 

 of which three were Leonids. At Bristol the sky 

 was watched at a later hour, but only one Leonid 

 was seen between 13 11 and 13 11 45™, after which 

 observations were discontinued. Mr. Prentice noticed 

 several minor showers of which radiant points at 

 4i°+29°, 42°+2i°, 53°+ I 3°. and 55°+ 8 4° were 

 the most actively pronounced." The shower of 

 Leonids was not expected to be abundant this year, 

 as the parent comet (1866 I) will not return until 

 1933. It sometimes happens, however, that a 

 moderately active display of Leonids occurs when 

 the comet is far removed from perihelion, as in 1879 

 and 1888. 



Comet Notes. — Baade's Comet, 1922 c, was 

 observed at Copenhagen on November 9 and at 

 Cambridge by Mr. G. Merton, using the Northumber- 

 land Equatorial, on November 11. It has a fairly 

 definite nucleus 10" to 20" in diameter, and a coma 

 il' in diameter. The stellar magnitude is variously 

 estimated at 9 and 10-5, the former being probably 

 nearer the truth. The brightness is slowly diminish- 

 ing, but the comet should be observable for some 

 months. The following orbit is from observations 

 on October 19, 28, November 11 : — 



T = i922 Oct. 27-252 GMT. 

 w = n8° 46'"3> 

 £2=220 (4 ,- 2 i'\zz-o. 

 i= 51 22''3/ 

 log?=o'353i8. 



Ephemeris for Greenwich Midnight. 



h 'nf ' s N - DecL log r - log A ' 



Nov. 25. 21 15 32 27 20' 0-3579 0-3150 



29. 21 25 36 26 20 0-3593 0-3222 



Dec. 3. 21 35 39 25 21 0-3608 0-3297 



7. 21 45 39 24 26 0-3625 >> . , 



11. 21 55 35 23 33 0-3643 0-3460 



15. 22 5 27 22 44 0-3663 0-3549 



The comet is well placed in the evening sky, high 

 up in the south-west ; it is visible in moderate 

 telescopes. The above path begins 3° S.E. of f Cygni, 

 and ends 3° S. of t Pegesi. It is important to observe 

 it as long as possible, in order to detect any deviation 

 from a parabola. 



NO. 2769, VOL. I IO] 



Mr. F. E. Seagrave has computed the two following 

 orbits of Comet Pons-YVinnecke from observations 

 made respectively before and after perihelion passage 

 in 1 '12 1 : — 



T = io>i June 12-9165. 

 u = 170 17' 18". 



n = 98 6' 29". 



»= l8 ° 54' 37*- 



log 9 =0-01737.;. 

 M = 59 2"-888. 

 Period =2 185-9 days. 



June 12-9276. 



170° 15' 56". 



98° 8' 19". 



18° 56' 33"- 



0-017409. 



58 7 "-i8 4 . 



2207-1 days. 



The next perihelion passage will be in June 1927. 

 The conditions will be very similar to those in 1921, 

 but the approach to the earth will probably be 

 closer ; search should again be made for meteors 

 in that year, since these are evidently spread fairly 

 widely around the comet's orbit. The perturbations 

 in the present revolution are small, there being no 

 approach to Jupiter. 



Report of the Paris Observatory for 192 i. — 

 This report shows that in spite of difficulties caused 

 by the war there is quite a large output of work. 

 The observations for three important star catalogues 

 have been completed, namely, (1) The supplementary 

 catalogue of Lalande stars; (2) tnat of 15,000 etoihs 

 de repevt of the Paris zone ; (3) that of 3000 funda- 

 mental stars ; they will be published in a few years. 

 The work on the Astrographic Chart is approaching 

 completion ; the 2500 copper plates, 26 :< 26 mm., 

 will be carefully stored, as it is suggested that they 

 may form a priceless record of the state of the heavens 

 in an age long after the paper copies have perished. 

 It is hoped that the Paris Astrographic Catalogue will 

 be completed in four or five years. 



It is noted that M. Krassowski of Varsovie has 

 undertaken the calculation of the perturbations of 

 Giacobini's Comet 1896 V which is expected early next 

 year. 



Full details are given of the system of Time signals, 

 which are under the direction of M. Bigourdan. 

 M. Hamy has been investigating the diffraction of 

 the images of stars and hopes to apply his results to 

 obtain an improved diameter of the sun. 



Photography of stars by the extreme red ravs has 

 been carried out experimentally, and it is proposed 

 to continue this work on Mont Blanc. The aim is to 

 study the possibilities of daylight star photography. 

 The report also deals with spectroscopic work on bright 

 stars, the sun and chromosphere, and several stars have 

 been photographed in three colours with colour screens. 



