54 



NATURE 



[March ii, 1920 



the council for the year : — Alloys, 220L ; steam- 

 nozzles, 150L ; hardness tests, 150/. ; and cuttint,' tools, 

 looi. The alloys research has been carried on at the 

 National Physical Laboratory, and the eleventh report 

 will be presented at an early datr. The construction 

 of the experimental apparatus for the steam-nozzles 

 research has been further delay for lack of funds, 

 but help has been promised by a grant of 500/. from 

 the Turbine Blade Research Committee of the 

 British Electrical and Allied Manufacturers' Asso- 

 ciation. It is intended to erect the apparatus 

 at the Dickinson Street Power Station, Manchester, 

 and the experiments will be conducted under the super- 

 vision of Prof. G. Gerald Stoney and Mr. S. L. 

 Pearce. Hardness tests have been carried out at the 

 National Physical Laboratory by Dr.- T. E. Stanton, 

 and it is hoped that reports will be presented tfiis 

 vear. A bibliography on cutting tools is being pre- 

 pared by Mr. G. W. Burley, and it is proposed to 

 collect information from makers and users of cutting 

 tools. The work of the wire-ropes research com- 

 mittee has been considerably delayed owing to the 

 war ; arrangements have now been made for exoeri- 

 mental work to be carried out at Woolwich Poly- 

 technic by Dr. W. A. Scoble. The work of the 

 refrig'eration research committee has been suspended 

 since 19 14; it is hoped that investigations may be 

 made shortly into the physical properties of the sub- 

 stances used in refrigeration. 



A CATALOGUE (No. 357) of rare books and manu- 

 scripts has just been issued by Messrs. Bernard 

 Qtiaritch, Ltd., ii Grafton Street, W.i, and is worthy 

 of perusal. It is of a fairly general character as to 

 the subjects, but two sections will appeal especially 

 to readers of Nature, viz. those dealing with natural 

 and physical sciences (21 pp.) and with periodicals 

 {13 pp.). Many scarce volumes and long runs are to 

 be found in these. The price of the catalogue is is. 

 We notice that Messrs. Quaritch are about to begin 

 the publication of the Journal of Pomology. It will 

 appear at quarterly intervals under the editorship of 

 Mr. E. A. Bunyard, who has secured the promise of 

 assistance from many experts. 



An illustrated book on "Weeds of Farm Land," 

 the work of Dr. Winifred E. Brenchley, of the 

 Rothamsted Experimental Station, is to" be pub- 

 lished by Messrs. Longmans and Co. It will deal 

 with various aspects of the weed problem, but 

 especially with the relations existing between weeds 

 and the soils and crops with which they are chiefly 

 associated. A survey will be given in the volume of 

 the present position with regard to the questions of 

 prevention, eradication, and uses of weeds, also of 

 their habits and method of distribution and the vitality 

 of buried weed-seeds. 



Readers of Nature who are interested in ancient 

 herbals and old-time gardening and agriculture should 

 see Catalogue No. 81 of Messrs. Dulau and Co., 

 Ltd., 34 Margaret Street, W.i, in which are to be 

 found particulars of 1000 works dealing with these 

 and other scientific subjects, many the property of 

 the late Sir Frank Crisp. An unusual feature is a 

 collection of volumes on sundials. 

 NO. 2628, VOL. 105] 



Our Astronomical Column. 



Bright Meteors. — ^A fine meteor was observed on 

 February 17 at 8h. 52m. by Mr. F. Wilson, Totteridge, 

 and Mr. S. B. Mattey, Plumstead. It was brighter 

 than Jupiter, and moved very slowly from a radiant 

 at 72"-t-43° near oAurigae. The approximate height 

 of the object was 67 to 30 miles, path 53 miles, and 

 velocity 10 miles per second. It passed from over 

 south-west of Needham Market to Woodbridge. 



Another very brilliant meteor was observed on 

 February 27 at 8h. 58m. by Mrs. Wilson and Miss 

 Cook, and also by Mr. S. B. Mattey at Plumstead. 

 The radiant was at about i7°+8° near the horizon 

 9° north of west. The height of the object was 53 to 



49 miles, path 95 miles, and velocity 12 miles per 

 second. It passed from over Lydd, Kent, to about 



50 miles east of Calais, France. Fireballs from 

 Auriga and Pisces have been recorded in previous 

 years at about the same dates as those of this year. 



Total Light of the Stars. — The late Prof. New- 

 comb laid stress on the desirability of obtaining this 

 observational constant, and several attempts have 

 been made to do so. The latest is by Mr. P. J. Van 

 Rhijn (Contributions from Mount Wilson Observa- 

 tory, No. 173). This paper shows that there is 

 illumination, which is probably due to (a) a faint 

 extension of the zodiacal light, including the Gegen- 

 schein, and (b) faint aurorae. The amount of these 

 was found by observing regions of the sky remote 

 from the Galaxy and assuming that the starlight in 

 these regions could be inferred from the observed 

 number of stars of each order of magnitude. The 

 amount of each of these is discussed, and it is con- 

 cluded that the total amount of light received from 

 all the stars in both hemispheres is equal to 1440 stars 

 of magnitude 100, Harvard visual' scale. The fol- 

 lowing are the values of extra-galactic skv brightness 

 per square degree found by different observers, the 

 unit being a star of magnitude 100 : — Newcomb, 

 0029; Burns, 0050; Abbot, 0075; Yntema, 0140; and 

 Van Rhijn, 0130. The magnitude of the full moon is 

 about — 12 ; it is, therefore, about 140,000 times as 

 bright as a star of magnitude 100, or a hundred 

 times as bright as all the stars together. 



Star Clusters. — Scientia for March contains the 

 fourth of a series of papers on clusters by Dr. Harlow 

 Shapley. Dr. Shapley quotes a remark that distance 

 introduces simplification in our study of the clusters ; 

 it makes apparent magnitudes equivalent to absolute 

 ones, since all the components an; at ])ractically the 

 same distance from us. He then proceeds to consider 

 the local cluster to which the sun belongs, which he 

 regards as defined by Dr. Charlier's research on the 

 distribution of the B stars in space. The conclusion 

 was that they form a flattened cluster, with greatest 

 diameter 4000 light-years. This is supposed to be 

 merely one unit out of many that go to make up the 

 galaxy. Its equatorial region is marked by a zone 

 of bright stars, to which attention was directed t)\ 

 Sir J. Herschel and Dr. B. A. (iould. Its plane is 

 inclined some 15° to the medial line of the i^^alaw . 

 Dr. Charlier puts the centre of the local cluster in 

 Carina, some 250 light-years from the sun ; while 

 Dr. Shapley makes the distance only 150 light-\ears. 



Since from analogy the cluster is likely to be 

 moving with respect to its neighbours, the two star- 

 drifts would appertain respectively to cluster and non- 

 cluster stars. It is left an open question to which 

 category the sun belongs. Viewed telescopically from 

 the Hercules cluster, the local cluster would seem (n 

 be mainly composed of B stars, with a smaller numbrr 

 of giant M ones. The sun would be of the 

 twentieth magnitude, too faint for visual observation, 

 though it might be photographed. 



