June 2, 1910] 



NA TURE 



409 



months. Amongst them are two which deal with the 

 saturation pressure of water vapour at temperatures outside 

 the range 50° C. to 200° C, covered by the experiments 

 of Drs. Holborn and Henning in 1908. The first paper, by 

 Drs. Scheel and Heuse, deals with temperatures between 

 0° C. and 50° C. They use the static method, measuring 

 the temperature by a platinum thermometer and the pres- 

 sure by the modified mercury manometer we noticed in 

 these columns some time ago. The second paper, by Drs. 

 Holborn and Baumann, deals with the range from 200° C. 

 to 376° C. Temperatures were measured bj' the platinum 

 thermometer, pressures by a weighted piston moving in a 

 brass cylinder. Except at the highest temperature the 

 three sets of measurements can be represented by formula; 

 of the type suggested by Thiesen, 



i.e. (/+273)log-4- = a(^-ioo)-3|(365-/)^-265*, 

 760 



where a and h are constants. 



Mr. W. p. Sexton informs us that the value of the 

 specific heat of the first four molecules of water of crj'Stal- 

 lisation in copper sulphate given by him in his note to 

 the Faraday Societ}-, referred to in N.\ture of May 5 

 (p. 292), should have been 0449, and not 0499, as stated 

 in our report. 



The issue of The Central for April is a memorial 

 number dealing with the life and work of the late Prof. 

 W. E. Ayrton, F.R.S. The number contains two memoirs 

 by Mr. Maurice Solomon and Prof. T. Mather, F.R.S. , 

 respectively, and is illustrated bj- four portraits of Prof. 

 Ayrton at various ages. A list of Prof. Ayrton 's scientific 

 publications completes the number. 



The first parts of two new works dealing, respectively, 

 with " Our Canaries " and " Cage-bird liybrids," have 

 been received from the office of Cage Birds. The works 

 will be published in monthly parts, price sixpence each, 

 and will provide keepers of canaries and breeders of canarj' 

 mules and British bird hybrids with full details relating 

 to the selection, breeding, and general management of 

 these cage birds, either for pleasure or profit. Coloured 

 plates and other illustrations add to the attractiveness of 

 each work. 



The Sleeping Sickness Bureau, under the direction of 

 its honorary managing committee, has issued a revised 

 edition of its brochure entitled " Sleeping Sickness : How 

 to avoid Infection." The pamphlet is for the use of 

 travellers and residents in tropical .Africa, and gives an 

 account of Glossina palpalis and illustrations of this and 

 other biting flies. Much useful information is provided as 

 to places where persons are liable to be bitten, and the 

 Steps to be taken to abolish and to prevent the spread of 

 tile fly. 



A COPY of the report of the Indian Association for the 

 Cultivation of Science for the year 190S, which was pub- 

 lished in Calcutta last year, has just been received. One 

 of the chief activities of the association is the arrange- 

 ment of lectures on scientific subjects, and we notice that 

 286 were given under the auspices of the association during 

 1908. The association also conducts a chemical laborator}-, 

 where students are encouraged to follow systematic courses 

 of work, and arranges for regular meteorological observa- 

 tions to be taken at its observatory and for their publica- 

 tion. The finances of the association appear to be in a 

 flourishing condition. In fact, the officers may be con- 

 gratulated upon the useful work which is being accom- 

 plished under their guidance. 



NO. 21 18, VOL. 83] 



OUR ASTRONOMICAL COLUMN. 



The Solar Constant. — In No. 4, vol. xxxix., of the 

 Memorie della Societa degli Spcttroscopisti Italiani Dr. 

 Gorczj'nski discusses the pyrheliometric obser\'ations of the 

 solar constant made at Crsj'nova (Polonia) during 1909. 

 The value obtained was 205 gr. cal./cm." min., and, from 

 a discussion of the values obtained at various obser\-atories 

 by different methods. Dr. Gorczynski concludes that this 

 value is ver^- near the truth. 



Origin of Binary Stars. — In No. 3, vol. xxxi., of the 

 Astrophysical Journal Prof. H. N. Russell discusses the 

 origin of binary stars from the point of view that they 

 are produced by the fission of rotating masses. He deduces 

 the conditions of such a mass which would precede and 

 follow the process of fission, and also shows that the avail- 

 able data derivable from existing systems are in accord- 

 ance with the theory. Finally, Dr. Russell concludes that 

 whilst the development of nuclei in the original nebula 

 must be invoked to account for the formation of star 

 clusters, it is more reasonable to suppose that binary- 

 systems have been produced by fission. 



The Astronomical Society of Antwerp. — The annual 

 report, for 1909, of the Soci^t^ d'Astronomie d'Anvers con- 

 tains a record of much, extremely useful, service per- 

 formed in the popularisation of astronomy. Popular 

 lectures in French and Flemish were given by various 

 members of the society, and were free to all ; further, they 

 weie well atte!;ded. There is a project on foot to obtain 

 facilities from the town authorities for the erection of a 

 larger observatory, and it is expected that the obiexrt will 

 be attained during the present jear ; the society' co^ild then 

 do more than ever to spread the study of the heavens. 



The interest in, and general ignorance concerning, 

 Halley's comet displayed by English crowds during the 

 past few weeks engender the wish that more could be 

 done for popular astronomy in England, and the present 

 moment seems favourable ; but it could probably only be 

 done by the private munificence of some friend of science. 

 There can be no two opinions as to the urgent need for 

 popular instruction in the oldest of the sciences. 



OBSERIATIOXS OF HALLEY'S COMET. 



'X'HERE is little more to record of Halley's comet yet; 

 as a popular spectacle, in England, its appear- 

 ance has been somewhat of a failure, and we shall have 

 to wait some little time before the results obtained 

 by astronomers in different countries are 'available. 

 Some amount of resentment has been expressed in the 

 popular Press at the feeble appearance of the famous 

 comet, but it should be clearly understood that it is our 

 hazy summer skies and the brightness of our northern 

 twilight that are to blame. In a letter to Prof. Turner 

 Mr. Knox Shaw, of the Helwan Observaton,-, describes it 

 as really a glorious sight, about May 11, far exceeding in 

 its glor)- comet 1910a ; it then had a straight tail 38° long. 

 Yet at Helwan there were onh* three fine nights during 

 the first fortnight in May. 



With his note in No. 20 of the Comptes rendus (May 17) 

 M. Esclangon gives four diagrams showing the progressive 

 development of the nucleus and its appendages between 

 February 13 and May 1 1 . On the former date the nebulous 

 head was nearly circular, but the ill-defined nucleus had 

 already two embryo extensions, which gave it a triangular 

 appearance. On .April 27 the head was parabolic, with the 

 nucleus a little behind the focus, and two jets forming a 

 broad V streaming behind ; there was also a bunch of ravs 

 issuing in the shape of a fan towards the sun. On 

 >Iay 10 this aigrette was larger and better defined, having 

 an angle of 70° and a length of about 30*, but the two 

 rear streamers were not so definite. Up to this time the 

 aigrette had appeared to be symmetrical with regard to the 

 axis of the comet, but on May ii it was appreciably dis- 

 placed, the angle between the axes of the aigrette and of 

 the comet being some 20° or 30°. M. Esclangon suggests 

 that this observation might indicate an oscillation of the 

 aigrettes such as was noted during the apparition of 183-;. 

 He also remarks upon the great length of tail, which on 

 May 16 was about 65°. corresponding to an actual length 

 of 020 astronomical unit. 



