August io, 1905I 



NA TURE 



15 T 



in a vacuum whrn subjected to the radiation of radium. 

 The disc beinj^ under two influences, namely, an increase 

 in the negative charge owing to the impact of the j3 

 electrons and a loss of negative charge owing to the 

 emission of a secondary radiation, the actual rate of 

 accumulation of the negative potential measured inversely 

 the rate cf produclion of the secondary' radiation. 



The Engineering .Standards Committee has issued a 

 report on the effect of temperature on insulating materials. 

 .\ series of measurements showing the influence of 

 temperatures ranging from 75° C, to 150° C. on the dis- 

 ruptive voltage, the resistance and the mechanical proper- 

 ties of the insulating materials used in industry, were 

 made by Mr. E. II. Rayner at the National Physical 

 Laboratory, by Messrs. Crompton and Co. at Chelmsford; 

 and by .Messrs. .Siemens Bros, and Co. at Woolwich. The 

 electrical properties of the materials do not seem to be 

 greatly influenced by exposure at the temperatures given, 

 but the material itself perishes on long-continued heating. 

 .An interesting point established is the extraordinary in- 

 crease in resistance of the insulating substances which, 

 owing to the removal of water, accompanies drying at 

 too" C. The price of the report is 5s. net. 



.•\n interesting Parliamentary return Just issued gives 

 some particulars of the first three months' working of the 

 Wireless Telegraph Act. Part of the return relates to 

 licences, seventy-eight applications for which have been 

 received ; the majority of these are for experimental pur- 

 poses, but a fair number are for commercial purposes. 

 No less than four companies have applied for licences to 

 establish stations to communicate with America ; two of 

 these have been granted, one is under consideration, and 

 the fourth is offered with an alteration in localitv. The 

 paper also ccntains particulars of Ihe working of the 

 arrangement Ijetwecn the Post OtTice and the .Marconi 

 Co. It seems that iii messages have been received by 

 the Post Office for transmission to outward bound ships, 

 of which 21 could not be delivered (in six cases at least 

 through the senders' fault in transmitting after the latest 

 guaranteed time). The number of messages received from 

 ships at sea is 1655, which, if it does not represent a very 

 great volume of business, still serves to show that the 

 system is beginning to develop in practical utility. 



A MOST interesting paper on a new carbon filament, read 

 recently by Mr. Howell before the .American Institute of 

 Electrical Engineers, is published in the Electrician for 

 July 28. The author claims to have produced a new 

 allotropic modification of carbon, so different are the 

 physical and mechanical properties of his filament, which 

 IS prepared in the following way : — An ordinary carbon 

 filament made from a solution of cellulose is baked to as 

 high a temperature as possible in an electric resistance 

 furnace; it is then "flashed" in the usual manner, and 

 afterwards again electrically baked. Although the first 

 electrical baking considerably afl'ects the final result, it 

 seems that the graphite coating deposited during flashing 

 undergoes a very marked change during the subsequent 

 baking, which is especially remarkable considering the 

 high temperature at which the deposit is formed. The 

 filament possesses a very much lower specific resistance 

 than ordinary filaments, and this is a disadvantage from 

 the point of view of practical lamp making ; but, on the 

 other hand, the resistance-temperature curve rises instead 

 of falls, which is a distinct gain, and will undoubtedly 

 confer on the lamp an indifference to fluctuations of line 

 voltage, and so enable it to be run at a high efficiency. 

 NO. 1867, VOL. 72] 



The inventor claims a useful life of 500 hours at a power 

 consumption of 2-5 watts per candle, which is an extremely 

 good result for a carbon lamp. 



The De La More Press will publish in the autunm " .\ 

 P'irst German Course for Science Students," by Prof. 

 H. (;. Fiedler and Dr. F. E. Sandbach. 



We have received a copy of the first volume of the 

 " Collected Researches " of the National Physical Labor- 

 atory. The volume contains five contributions, viz. : — 

 An analysis of the results of the Kew magnetographs on 

 " quiet " days during the eleven years iSgo-igoo, by Dr. 

 Charles Chrce, F.R.S. ; the high-temperature standards 

 of the National Physical Laboratory, by Dr. J. A. Harkcr ; 

 the construction of some mercury standards of resistance, 

 w'ith a determination of the temperature coefficient of 

 resistance of mercury, by Mr. F. E. Smith ; the range of 

 solidification and the critical ranges of iron-carbon alloys, 

 by Dr. H. C. H. Carpenter and Mr. B. F. E. Keeling; 

 and the resistance of plane surfaces in a uniform current 

 of air, by Dr. T. E. Stanton. All the papers have been 

 published previously, three of them in the Transactions 

 of the Royal Society and two in journals of other scientific 

 bodies. As Lord Rayleigh says in a preface to the 

 volume : — " A multitude of other problems of scientific 

 and technical importance press for solution. .Soine of 

 these are already in hand, but the rate at which progress 

 can be made will depend in great measure upon the 

 amount of support which may be forthcoming from those 

 more immediately concerned in the development of in- 

 dustry. It is hoped that the publication of the present 

 volume may serve as a stimulus, by showing the character 

 of the work of which the Laboratory and the Staff are 

 capable." 



Prof. N. Z\Kti)Xoi publishes in vol. xxxvi. of the 

 Memoirs of the Russian Geographical Society the 

 herpetological and ichthyological results of his journeys 

 in eastern Persia. The Reptilia are represented by 72 

 species, the .Amphibia by 6 species, and the fishes by 17 

 species, many of which, especially among the first 

 division, are new species described by Prof. .A. M. 

 Nikolsky. 



The last volume of the Memoirs of the Russian Geo- 

 graphical Society, for ethnography (vol. xxv., i), contains 

 a very valuable bibliography, by M. Baltramaitis, of every- 

 thing that has been printed about Lithuania (8514 titles), 

 its geography, history, law, statistics, and ethnography, 

 including folklore. This volume, which covers 614 pages, 

 is followed by an appendix, which contains a list of 

 Lithuanian and old Prussian books printed from the year 

 '553 t° "JOS (2665 titles). The whole is admirably indexed. 



Notice is given by the Clarendon Press of the first part 

 of a new book on " Elementary Chemistry," by Mr. 

 F. R. L. Wilson and Mr. G. W. Hedley. According to 

 the preliminary announcement which has reached us, the 

 ultimate object of the authors is " the cultivation of a 

 scientific habit of mind in the pupils, through the medium 

 of chemistry, rather than the mere acquisition of the facts 

 of science." 



Mr. John Hevwood has published a fourth edition of 

 Mr. R. L. Taylor's " Student's Chemistry." The book 

 has been enlarged and revised by Mr. J. H. Wolfenden, 

 and an appendix on the radio-active elements and an 

 introduction to the study of organic chemistry has been 

 added. The volume contains more than six hundred 



