January 21, 19 15] 



NATURE 



57^ 



northern storms. During the past thirty-seven years 

 the harbour of San Pedro (near Los Angeles) has 

 only been silted up five times by floods, although the 

 latter are of frequent occurrence. When the first 

 rain is steady it soaks into the land, and no floods 

 occur; but during the next period of rainy weather 

 they generally take place. Dr. Carpenter's useful 

 paper should be read in conjunction with Prof. A. G. 

 McAdie's elaborate memoir on the " Rainfall of Cali- 

 fornia " (Nature, October 15, 1914). 



It is not so long ago that Punch published a cartoon 

 of artists painting pictures intended to represent "old 

 masters," of which one-half had been restored bv a 

 particular process. In the Museums Journal Mr. I. J. 

 Williams, of the Welsh National Museum, describes 

 his experiences in cleaning pictures himself after 

 vainly attempting to obtain satisfactory results by 

 employing outsiders. The process is, of course, com- 

 paratively simple, involving nothing more than rubbing 

 off the old varnish with cotton-wool dipped in a mix- 

 ture of four parts of methylated spirit to one of 

 turpentine, but he finds that considerable skill is 

 required in stopping the process at exactly the right 

 stage. With a view to the future preserv-ation of the 

 pictures it would, however, be desirable to make very 

 careful inquiries as to the character of the varnish 

 subsequently used, as it is not improbable that the old 

 varnishes were better than any now obtainable. 



Owing to the decreased output of scientific work 

 in consequence of the war the concluding numbers of 

 Science Abstracts for the year 1914 are somewhat 

 less extensive than usual. The physics part consists 

 of forty pages of abstracts and four of index, and 

 the electrical engineering part of thirt\--one and four 

 pages resp>ectively. The actual number of abstracts 

 in the two parts is 104 and sixty-two. The average 

 length of the engineering continues to be greater than 

 that of the physics abstract, mainly on account of 

 descriptions of engineering plant. Both sections of 

 the publication continue to supph' up-to-date and trust- 

 worthy information as to the advances made in many 

 fields, and it is difficult to see how any scientific or 

 technical worker in either subject could now dispense 

 with Science Abstracts. 



According to an editorial note in the Scientific 

 American for December 26, 1914, a series of articles 

 will be published early in the present year dealing with 

 the necessity of encouraging in every possible wav the 

 scientific researcher in order to make the industries 

 of .\merica more independent of Europe. The editor 

 is of opinion that many manufacturers who at present 

 depend on Europe for some portion of their raw 

 material for technical processes could, by stating their 

 difficulties to a man of science willing to undertake 

 the necessary research, obtain at a relatively small 

 cost information which would place them on a much 

 firmer footing. We have no doubt these articles will 

 be read with interest in this country, as the attitude 

 of the British manufacturer towards research is by 

 no means so cordial as it ought to be. 



A POPULAR edition of Prince Kropotkin's ■' Mutual 

 Aid : A Factor of Evolution," has been published by 

 NO. 2360, VOL. 94] 



Mr. William Heinemann, at the price of is. net. This 

 cheap re-issue of an im|X)rtant work appears at an 

 opportune moment. Many German writers are excus- 

 ing the horrors of the war by representing them as 

 unavoidable consequences of the struggle for exist- 

 ence. As our review of the first edition of " Mutual 

 Aid," in the issue of Nature for January i, 1903 

 (vol. Ixvii., p. 196), pointed out, Prince Kropotkin 

 shows that in the case of animals, there is ver}- little 

 evidence of any struggle for existence among members 

 of the same species, and no justification can be found 

 for the crude conception of Darwinism which places 

 selfish interests among the desirable attributes of the 

 human race. We welcome this cheap edition of Prince 

 Kropotkin 's noteworthy exposition of evolutionar}' 

 ethics, and we hope it will have the wide circulation 

 its lucidity and charm deser\'e. 



The Cambridge L'niversit}- Press will shortly issue 

 a new edition — the third — of "' Zoology," by Drs. Ship- 

 le\' and MacBride. The work has been thoroughly 

 revised, many portions being re-written, and several 

 new illustrations added. — Messrs. Methuen and Co., 

 Ltd., announce the forthcoming publication of a 

 further selection of Sir E. Ray Lankester's popular 

 science articles. It will be entitled " Diversions of a 

 Naturalist." 



OUR ASTRONOMICAL COLUMN. 



Spectral Line Displacements at the Sun's Limb. — 

 As a further research in connection with the work 

 carried on at the Kodaikanal Observatorj- on the dis- 

 placement of spectrum lines at the sun's limb, Mr. 

 A. A. Narayana Ayyar contributes to Bulletin No. 44 

 of the Kodaikanal 6bservator>- the results of his work 

 on the displacements at the sun's limb of lines sensi- 

 tive to pressure and density. It is pointed out that 

 certain lines, particularly those of calcium and sodium, 

 are much more sensitive to pressure and density than 

 iron lines, and that therefore the limb shifts of such 

 lines should provide a much more rigorous test as to 

 whether there is a large difference of pressure and 

 density between the sun's limb and centre. The paper 

 gives the experimental details, and the result arrived 

 at is that the difference of pressure and density be- 

 tween the limb and centre is ver}- small, a conclusion 

 in agreement with that derived by Messrs. Evershed 

 and Royds. The balance of evidence, as the author 

 states, is in favour of slightly lower pressure and 

 density at the limb than at the centre of the disc. 



St.^tistics of Spectroscopic Binary Stars. — In the 

 Arkiv for Matematik, Astronomi och Fysik (vol. x.. 

 No. 6) of the Stockholm Academy, Dr. Sven Wicksell 

 contributes a paper on the statistics of spectroscopic 

 binar\- stars. Referring in the first instance to the 

 important investigations and discussions by Campbell, 

 Schlesinger, Baker, Ludendorff, etc., he attempts to 

 find out other interesting properties of spectroscopic 

 binaries. Constructing a card-catalogue of 440 

 binaries, he found it was composed of 104 systems, of 

 which the period was known, sevent}--nine in which 

 the semi-amplitude of radial velocitj- was known and 

 seventy-five in which the excentri'cit}.' was known. 

 All these he divided into four classes, according to 

 their spectral t\pe, and arranged them in tabular 

 form. The investigation is devoted to the studv of 

 the frequency cunes of the period, the explanation of 

 the existence of two groups of periods, a reference 

 to Shapley's investigation of eclipsing binaries, etc.. 



