September 29, 1904] 



NA TURE 



537 



year to discuss the means of advancing our knowledge of 

 the relation between solar and terrestrial changes. 



Sir John Eliot's address has already appeared in these 

 columns, so that attention here will be restricted to the 

 subsequent proceedings of the subsection. 



With Sir John Kliot in the chair, the first paper on Friday 

 was by Father Cortie, who summed up the results of all 

 the observations of sun-spot spectra made at Stonyhurst 

 during the period 18S3-1901. One of the chief points of the 

 paper was to show the great importance of the elements 

 vanadium and titanium, the lines of these elements being 

 more frequently widened than those of any other. Refer- 

 ence was also made to widened-line crossings and to o.\ygen 

 in the spectra of sun-spots. 



Sir Norman Lockyer then followed with a short summary 

 of his work on the classification of stars according to their 

 temperature since he gave the Rede lecture in 1871. The 

 chief feature of the paper was to show that by paying special 

 attention to the results obtained with a small camera having 

 calcite and quartz to replace the glass lens and prism used 

 in his earlier work, he was enabled to bring a more efficient 

 check on the classification from the point of view of the 

 e.xtension of the spectrum in the ultra-violet than he could 

 with the glass optical parts. The result of this inquiry 

 confirmed the chemical classification in every respect. 



The e.xtension in the ultra-violet part of the spectrum as 

 a criterion of stellar temperatures was the subject of a paper 

 by Mr. H. F. Newall, who was inclined to question this 

 criterion based upon the ultra-violet extension. He referred 

 to observational evidence, which displayed sometimes perplex- 

 ing discrepancies between the relative intensities of the blue 

 and the red ends of the spectrum in different stars. The 

 point raised was, how far was the present criterion of stellar 

 temperature based upon the observed behaviour of gaseous 

 radiation as opposed to the radiation of solid bodies? He 

 said, in conclusion, that it was not impossible that we should 

 be forced to regard extension in the ultra-violet regions as 

 a sign of differences and not of high temperature. 



The paper on the short-period barometric see-saw and its 

 relation to rainfall, by the present writer, was an ex- 

 tension of a paper which has previously been printed in this 

 Journal (vol. Ixx. p. 177). The chief point was to show 

 how very closely rainfall curves were associated with curves 

 representing the inverted barometric changes. The regu- 

 larity of the barometric see-saw mentioned above suggested 

 that there may possibly be found to exist a method here of 

 forecasting wet and dry years over a large portion of the 

 earth's surface. 



After a brief interval for lunch, the meeting was con- 

 tinued. Dr. Shaw taking the chair in the absence of Sir 

 John Eliot. 



Prof. Birkeland (Christiania) spoke about the relationship 

 between sun-spots and aurone. The chief feature was to 

 indicate that " stream lines " from the sun could only reach 

 the earth's atmosphere between very narrow limits, and 

 these in high latitudes, and further that only spots on a 

 restricted portion of the solar disc in relation to the position 

 of the earth would have any terrestrial effect. In this way 

 he suggested a means of explaining the narrow curtain-like 

 form of the aurora and its occurrence chiefly in high 

 latitudes. 



.A short paper by M. .Angot (Paris) described a result 

 which he had derived from an examination of Wolf's sun- 

 spot numbers. He found that, by taking the relative 

 number at a sun-spot minimum and also about a sun-spot 

 maximum, small relative numbers at a minimum are 

 followed by small numbers at a maximum, and large numbers 

 at a minimum by large numbers at a maximum. .As the 

 last minimum (igoi-7) was small, the next maximum, he 

 suggested, will be small also. .As another investigation 

 points to the next maximum being comparatively large, it 

 will be interesting to see which occurs. 



The results of an investigation of the upper air over the 

 Mediterranean by means of flying kites from a steamer 

 were described by M. Teisserenc de Bort. He showed that 

 although on the average greater elevation meant greater 

 wind velocity, there were alternately strata of large and 

 small velocities. Tiiis fact explains why sometimes attempts 

 at getting kites to fiy above certain elevations have failed. 

 Both Mr. Rotch and Dr. Shaw spoke on this interesting 

 question. 



NO. 1822, VOL. 70] 



Conunander Hepworth described the relation between 

 pressure, temperature, and air circulation in the South 

 Atlantic Ocean, the result of a large piece of research work 

 i]i which 3300 ships' logs had been utilised. In the absence 

 of Prof. K. Angstrom, his two papers, on the ultra-violet 

 absorption spectrum of ozone and the existence of that gas 

 in the atmosphere, and an instrument for the measurement 

 of the radiation from the earth, were taken as read, and the 

 meeting closed for the day. • 



On Monday, the second day on which this subsection 

 met, Sir J. Eliot being in the chair, the reports of the 

 seismological and kites committees were briefly summarised 

 by Dr. Milne and Dr. Shaw respectively. 



Mr. A. L. Rotch (U.S. .A.) described the results of the 

 experiments he has been making with kites at the Blue 

 Hill O.bservatory in order to determine the temperature of 

 the air in cyclones and anticyclones. Sir David Gill spoke 

 about an attempt he had made to state the problems in 

 practical astronomy which press for solution. Among these 

 he mentioned the apparent discordance between the value of 

 the constant of aberration as derived from direct observation 

 (2o"-52) and that obtained by combining the measured value 

 of the sun's parallax (8"-8o) with the known velocity of 

 light, which gives a value of the aberration constant (2o"-48). 

 The discussion in the paper confined itself to the means to 

 be adopted for perfecting the determinations of the solar 

 parallax, the constant of aberration, and the mass of the 

 moon. Reference was also made to the variation of lati- 

 tude, to the Lcewy-Gomstock method for determining the 

 aberration constant, to recent improvements in methods of 

 meridian observation, and to the value of old series of 

 observations. 



Dr. W. N. Shaw opened the discussion on a memorandum 

 adopted by the committee of the council on the suggested 

 uniformity of units for meteorological observations and 

 measurements. Several speakers gave their views on the 

 subject, but no definite conclusion was arrived at. The 

 general opinion seems to be that either to alter or put 

 additional scales to the barometers and thermometers would, 

 from a practical point of view, be detrimental to the observ- 

 ations themselves. It was suggested that such units might 

 be adopted in the discussion of meteorological problems, the 

 conversions to the new scales being made after the observ- 

 ations had been collected at the central oftice. From the 

 physical standpoint the subject was not discussed. 



in a paper on the masses of stars. Dr. H. N. Russell 

 pointed out that the average mass of fifty-five binary stars 

 is about three times that of the sun. Groups of stars with 

 very different spectra, magnitudes, and proper motions have 

 almost the same average mass. Thus it was concluded that 

 stars vary much less in mass than in other characteristics. 



The third and last meeting of this subsection took place 

 on Wednesday, Sir John Eliot being in the chair. The first 

 two items on the programme were the reports of committees 

 on the F'almouth Observatory and on observations of Ben 

 Nevis. In the absence of Prof. O. Backlund (St. Peters- 

 burg), his paper on some results of researches on the comet 

 Encke was taken as read. 



The writer described briefly the spectroheliograph 

 recently erected at the Solar Physics Observatory, South 

 Kensington. This instrument, ■which is now in fair adjust- 

 ment, is used for photographing the sun in monochromatic 

 light.' The numerous photographs shown gave an idea of 

 the efficiency of the instrument, and they are now being 

 daily secured, weather permitting. Composite pictures in 

 " K " light were shown, the " limb " and " disc " of the 

 sun being taken on one plate. Many of the photographs 

 showed rapid solar changes, one enormous prominence 

 iq2,ooo miles in length increasing to 216,000 miles in five 

 hours, its height changing from 55,000 miles to 60,000 miles 

 simultaneously. 



In a paper on the unsymmetrical distribution of rainfall 

 about the path of a barometric depression. Dr. H. R. Mill 

 showed that, for the British Isles, the area of heavy rain- 

 fall, in nine cases out of ten, lay on the left of the cyclone's 

 path, and in advance of the centre. This relationship 

 suggests that a more definite basis for forecasting heavy 

 rains becomes available if it be possible to ascertain 

 previously the path of the cyclone's centre. 



Miss Hardcastle read Miss F. E. Cave's paper, which 

 contained some further results she has obtained relative to 



