652 



NATURE 



[February ii, 1915 



were observed in each case, especially in declination. 

 The Survey, it seems, has decided that, beginning 

 with 1913, all the results of magnetic observations will 

 be referred to the " International Standard of the 

 Department of Terrestrial Magnetism of the Carnegie 

 Institution of Washington." This entails a reduction 

 of-one-tenth per cent, in the values of horizontal force 

 previously published. An interesting question of the 

 near future promises to be what this " international 

 standard " really means, and how it is to be main- 

 tained constant. 



In view of the recent report to the Board of Agri- 

 culture on the possibility of reviving the flax industry 

 in Great Britain, a paper on the field and industrial 

 retting of the fibre read before the Society d'Encourage- 

 ment de 1 'Industrie Nationale {Bulletin, vol. cxxi., 

 p. 153) by M. Albert Durand, the general secretary of 

 the Comite Linier of France, has especial interest. An 

 account is given in this paper of the different methods 

 of retting of flax now used in France, as well as of 

 the new mechanical and biochemical processes which 

 have been the subject of trials on the large scale. It 

 is interesting to note that M. Durand considers the 

 policy of inaugurating central retting establishments, 

 which was proposed in the report to the Development 

 Commission, as one that could be adopted with 

 advantage in France, The account given of the recent 

 processes of Feuillette and Peufailiet for retting flax, 

 illustrated as it is by numerous photographs, is a 

 Sf>ecial feature of the paper. 



Science Progress for January contains a vigorous 

 editorial article on militarism and party politics, 

 a criticism by Dr. H. G. Plimmer of Mr. 

 T. A Cook's recent work on the "Curves 

 of Life," and a survey of the problem of 

 vitalism by Mr. Hugh Elliot. Mr. Rhys Jenkins 

 contributes an interesting article on the international 

 struggle for manufactures as illustrated by the histon.' 

 of the alum trade, Mr. Allan Ferguson gives a sum- 

 mary of recent work on capillary constants and their 

 measurement, and Dr. J. N. Pring reviews the ques- 

 tion of the formation of ozone in the upper atmosphere 

 and its influence on the optical properties of the sky. 

 Dr. Edridge-Green deals with colour vision and colour 

 vision theories, a subject which at the present time "is 

 in a state of chaos," and Mr. C. E. Wallis gives an 

 interesting comparison of ancient and modern 

 dentistry. 



Engineering for January 15 contains an article on 

 the balancing of high-speed machinerv- by Messrs. 

 H. D. Wheeler and R. V. Southwell. After giving a 

 clear account of the nature of the problem, the authors 

 describe their optical arrangement in use at Messrs. 

 Lawrence Scott and Company's works for the accu- 

 rate balancing of high-speed armatures. The arma- 

 ture" is supported in ball bearings which can move in a 

 horizontal direction at right angles to the shaft against 

 the action of springs which normally keep the bearings 

 central. The armature is driven by a narrow strap 

 which runs vertically on to and oflf the armature. 

 At a certain speed depending on the size of the arma- 

 ture and the strength of the springs, the two bear- 

 Np. 2363, VOL. 94] 



ings begin to oscillate in the same direction, showing 

 that one side is heavier than the other. At a higher 

 speed generally about double the former, the bearings 

 again oscillate but now in opposite directions, showing 

 a want of dynamic balance. By means of a circular 

 disc with an involute slot in it, fixed on one end of 

 the shaft, light from the vertical filament of a lamp 

 placed under the bearing is focussed on a screen after 

 reflection at a small mirror which rocks about a ver- 

 tical axis as the bearings move. By means of the 

 curve traced by the spot of light the proper positions 

 of the balance weights can be found more quickly and 

 more accuratelv than bv the " chalk mark " method. 



OUR ASTRONOMICAL COLUMN. 



The Red Region in the Spectra of W^olf-Rayet 

 Stars. — In the Cotnptes rendus for January 25 (vol. 

 clx., p. 124) a note is presented by M. J. Bosler on an 

 investigation which he has carried out at the Meudon 

 Observatory on the study of the red region of the 

 spectra of \\'olf-Rayet stars. The advance in the mag- 

 nitude and efficiency of astronomical equipment renders 

 a more minute study of the spectra of faint stars 

 possible, and the bathing of photographic plates opens 

 up new regions of the spectrum for close inspection. 

 M. Bosler describes here the result of the work on 

 fifteen ^Volf-Ravet stars, seventy-five cliches in all 

 having been obtained with exposures varying from 

 two to three and a half hours. In the communication 

 he gives a short table, reproduced below, showing the 

 wave-lengths and intensities of several of the lines in 

 the spectra of these stars, which he considers are of 

 more special interest. In the brief discussion he refers 

 to the spectra of novae and their points of semblance 

 with these bright-line stars, and is led to the view 

 that the Wolf-Rayet stars are only the enfeebled re- 

 mains of novae which have appeared in the course of 

 past centuries. The following table embodies the data 

 in five of the stars mentioned above, the figures in 

 brackets indicating the intensities of the lines : — 



B.D. 3821 + 39° Mag. 71 (7 plate*): 7" (s) 691(2) 6675(2) 6563 (sHa) 



643(2) 6395 (2) 624(1). 



B.D. 4001+35° Mag. 8-5 (6 plates) : 711(2) 691(2) 677(2) 6678(3) 



6563 (sHa) 643 (i) 6395 (i). 



B.D. 4013+35= Mag. 8-0 (8 plates): 6718(3) 664(7) 657 (sHa) 6425(2) 



6300(1) 624(?). 



B.D. 3639+30'- Mag. 9-5 (8 plates): 6717(2) 6570 (2oHa) 630(7). 

 B.D. 3571+43° Mag- 7'5 (' P'ate): 6715(1) 6563(5Ho) 642(2). 



Aid to Astronomical Research.— In a communica- 

 tion to Science (vol. xli., No. 1046, January 15, 1915) 

 Prof. E. C. Pickering directs attention to the great 

 success of research funds, and points out the large 

 returns which can be obtained from relatively small 

 grants to suitable persons. Believing that the greatest 

 return in astronomical output can be obtained by 

 moderate grants to leading astronomers, he has ad- 

 dressed a letter to twelve American astronomers ask- 

 ing them to make a statement showing how theyj 

 would apply a grant supposing it consisted of one 

 thousand dollars a year for five years. In the com- 

 munication in question Prof. Pickering publishes the 

 replies he has received, and all without exceptlonj 

 would welcome such a grant. An unexpected result, 

 of the request was that in nearly every case the prin- 

 cipal need proved to be for assistants. The question | 

 now arises whether the money can be obtained, but if j 

 all cannot be secured, Prof. Pickering suggests that , 

 astronomers with fewer assistants should receive pre- ; 

 cedence. In some cases it Is hoped that those in- ; 

 terested in a particular observaton,- may be willing to ! 

 supply its needs. f 



