374 



NATURE 



[July io, 19 19 



ability. Altogether, this bulletin constitutes a valu- 

 able contribution to our knowledge of reinforced 

 concrete frames. 



Messrs. Baillicrc, 'liiidall, and Cox are adding to 

 their Industrial Chemistr\- Series "Animal Proteids," 

 H. G. Bennett; "The Carbohydrates," Dr. S. Rideal ; 

 and "The Industrial Gases," Dr, M. C. Greenwood. 

 The Cambridge University Press will shortly publish 

 "An Enquiry concerning the Principles of Natural 

 Knowledge," Prof. A. N. Whitehead, which will be 

 divided into four parts, dealing respectively with the 

 Traditions of Science, the Data of Science, the Method 

 of Extensive Abstraction, and the Theory of Objects. 

 Messrs. G. G. Harrap and Co. are publishing imme- 

 diately " Physical Chemistry," Prof. A. T. Lincoln, 

 and "An Inli-(iduction to ClKMniral (W-rman," 1^. \'. 

 (jrecnlicltl, with an introduction, notes, word-lists, 

 and a vocabulary of (ierman chemical terms. Messrs. 

 Longmans and Co. have in the press "Elements of 

 Vector Algebra," Dr. L. Silberstein. Sir Isaac Pitman 

 and Sons, Ltd., have just begun the publication of 

 "Pitman's Technical Bookshelf." It is a record of 

 their forthcoming and recent publications in science 

 and technology, and contains also brief abstracts of 

 articles from the technical Press. We learn from it 

 that the following books may be expected shortly : — 

 "Gas and Oil Operation," J.'Okill; "Storage-Battery 

 Practice," R. Rankin; "A Preparatory Course to 

 Machine Drawing," P. W. Scott ; a new edition, the 

 fourth, of "Whittaker's Electrical Engineer's Pocket- 

 Book," edited by R. E. Neale and completely re-written ; 

 and a new and enlarged edition of " Poole's Practical 

 Telephone Bock." Messrs. J. Wheldon and Co. have 

 nearly ready "A Synoptical List of the Accipitres or 

 Diurnal Birds of Prey," part i. (Sarcorhamphus to 

 Accipiter), H. Kirke Swann. The edition is limited 

 to 200 copies, only 100 of which will be offered for 

 sale. Messrs. Witherby and Co. have in the press 

 part i. of " A Geographical Bibliography of British 

 Ornitholot^'- " (arranged under counties) from the 

 earliest times to the end -of 1918, W. H. Mullens, 

 H. Kirke Swann, and the Rev. F. C. R. Jourdain. 

 The work will be completed in six parts. 



The catalogues of Messrs. J. W'heldon and Co., 

 38 Great Queen Street, W.C.2, are always worthy of 

 perusal. The latest one (new series. No. 87) is 

 especially so, being a verv complete and classified list 

 of nearly three thousand books in zoological science 

 arranged ujider the headings of Protozoa and Rotifera ; 

 Annelida ; Hydrozoa, Polyzoa, Spongia ; Echinoder- 

 mata; Crustacea; Insecta; Mollusca ; Marine Biology; 

 Parasitology, etc. ; Pisces (including Fisheries) ; Reptilia 

 and Batrachia ; Aves ; Mammalia (faunas) ; Cetacea and 

 Pinnipedia ; Domestic Animals ; Primates (and Man) ; 

 General Zoology; Natural History; Biology, Anatomy, 

 etc. ; and Evolution, Heredity, Hybridity. Many very 

 scarce works are included. The catalogue is certainly 

 one to be consulted. 



OUR ASTRONOMICAL COLUMN. 



The Eclipse and Wireless Telegraphy. — It will 

 be remembered that a programme of observation was 

 arranged to detect possible effects of the eclipse of 

 May 29 on the transmission of Hertzian signals, and 

 an interesting experience of this nature is reported 

 by the French military radio-telegraphic authorities. 

 There is at the observatory at Meudon a wireless 

 reception apparatus, which on the day of the eclipse 

 was arranged to receive the special signals sent from 

 the Island of Ascension. It has been found that wire- 

 less messages from that place can be heard by night, 

 though not by day, but during totality, when the 

 shadow projected by the moon passed between 

 NO. 2593, VOL. 103] 



Ascension and Meudon, the signals from Ascension 

 were heard strongly. They then decreased in inten- 

 sity, and ceased completely when the eclipse ended. 



The Parallax of the Pleiades. — Prof. Kapteyn has 

 proposed (Contributions Mount Wilson Observatory, 

 No. 82) an indirect method of finding the mean 

 parallax of the stars of a cluster by counting the 

 number of stars of different magnitude it contains. 

 The method requires a knowledge of the law of dis- 

 tribution of stars of different luminosity or absolute 

 magnitude in the cluster, but if this is known, since 

 apparent magnitude is a function of luminosity and 

 parallax, it is possible to evaluate the latter from 

 the data by formula. Dr. W. J. A. Schouten, of 

 Aalten, Holland, is applying this principle to find the 

 distance of star clusters, and gave thirteen of his 

 results in the Observatory for March, the parallax of 

 Praesepe being 0024", and the largest of the re- 

 mainder 0-004". He continues this in the June issue 

 by giving details of his research on the Pleiades, and 

 incidentally gives a valuable list of existing catalogues 

 of the group. From the counts of stars of different 

 magnitudes in five of these, in combination w'ith a 

 luminosity curve formed by Prof. Kapteyn, he deduces 

 five values of the parallax which are in close accord- 

 ance, and give a mean value 0-036", with a probable 

 error ±0010". Former determinations by Prof. 

 Kapteyn and Prof. Plummer by other indirect 

 methods, gave 0-018" and 0-024" respectively. Dr. 

 Schouten is encouraged to think that the comparative 

 accordance of the results is some confirmation of his 

 method. 



Painting the Corona. — On the occasion of the total 

 solar eclipse of June 8 last year (1918), which was 

 observed with some success from stations in 

 the United States, an unusual effort was made to 

 obtain a picture of the phenomenon in its true colours. 

 Mr. E. D. Adams, of New Vork, a benefactor to 

 science, who joined the U.S. Naval Observatory 

 eclipse party, took the responsibility for this, and, 

 as colour photography was out of the question, en- 

 listed the services of Mr. Howard Russell Butler, a 

 portrait painter of repute, who has developed a short- 

 hand method of noting both form and colour. Having 

 prepared a drawing card with circles, radii, and 

 angles marked, and having made himself mentally 

 familiar with the kind of picture that might be seen, 

 Mr. Butler utilised the 112 seconds of totality at his 

 disposal bv making a rapid sketch of the corona and 

 prominences as he saw them, and wrote numbers on 

 points and regions to indicate their colour according 

 to his numerical colour-scale. The artist's first 

 drawing was afterwards amended as to contours of 

 luminosity bv comparison with photographs, and then 

 completed. The painting, which shows not only the 

 prominences and corona, but also the sky around, 

 was exhibited at the American Museum of Natural 

 History, and a copy forms the frontispiece to Natural 

 History, the journal of the museum, for March 

 last. 



T' 



THE BRITISH SCIENTIFIC PRODUCTS 



EXHIBITION. 

 HE second British Scientific Products Exhibition 

 promoted bv the British Science Guild was 

 opened at the Central Hall, Westminster, on Thurs- 

 day, July 3, and it will remain accessible to the public 

 until August 5. It will be remembered that the first 

 exhibition was held in King's College last August, 

 but owing to the arrangements of the college, due to 

 demobilisation, it was found impossible to hold the 

 present exhibition there. Last year's exhibition was 



