354 



NATURE 



[February 9, 1905 



in the horary rate was apparent at i6h., and as the fog 

 became denser the observations were discontinued. 



Two of the Leonids seen were as bright as Jupiter, 

 whilst several others were as bright as, or brighter than, 

 first magnitude stars. One of these flashed out in the 

 north-west at i4h. 3Sm., traversed the path 3i5° + 57° to 

 3i8°-|-soi°, and left a short streak which lasted for about 

 30 seconds. 



A few slow, yellow meteors from a radiant in Aries at 

 43° + 21°, and some swift streaking meteors from a radiant 

 in Leo Minor at i44°+37°, were also seen. 



Spectra of 7 Cvgni, o Cams Minoris and € Leonis. — 

 In part vii. vol. cxiii. of the Sitzungsberichte der Kais. 

 Akad. der Wissenschaften, Herren E. Haschek and K. 

 Ivostersitz publish the results of the reductions of the spectra 

 of 7 Cygni, Procyon and e Leonis. After discussing in 

 detail the methods of measurement and identification em- 

 ployed in the reduction, and the general and specific char- 

 acteristics of each spectrum studied, the authors give a 

 table of the wave-lengths and intensities of the lines for 

 each star. The coincidences of each line with lines in the 

 arc and spark spectra of terrestrial elements, as determined 

 by Exner and Haschek, are also given, and in the last 

 column of each table the " probable origins " of many of 

 the lines are set down. Amongst the latter may be noted 

 the rarer elements Vb, Pr, Sa, Nd, La, Pt, Wo, Gd, Eu, &c. 



About 140 lines between \ 4250 and \ 4534, 190 lines 

 between X 4126 and A 4550, and about 270 lines between 

 \ 4215 and \ 4702 are given in the spectra of 7 Cygni, 

 a Canis Minoris and e Leonis respectively. 



Systematic Survey of Double Stars. — No. 99, vol. xvi., 

 of the Publications of the Astronomical Society of the 

 Pacific is devoted to an address on double stars read 

 before the International Congress of Arts and Sciences at 

 St. Louis by Prof. R. G. Aitken. 



After discussing the work already performed in this field. 

 Prof. Aitken described a systematical survey undertaken 

 by Prof. Hussey and himself. All stars down to the ninth 

 magnitude as given in the Bonn Durchmusterung were 

 placed on the observing list, and the sky from the North 

 Pole to —22° declination was equally divided for observ- 

 ation between the two observers. 



The programme arranged for the observation of each star 

 on the list on at least one good night, and all double stars 

 discovered with a separation of 5" or less were to be 

 measured on at least two nights and catalogued. On 

 September 10, Prof. Hussey had discovered 1035 and 

 Prof. .Aitken more than 875 new pairs. Seventy-three per 

 cent, of these are separated by 2" or less, and 142 are very 

 close pairs in which the separation does not exceed o"-25. 

 Of similar pairs to the latter the previously published cata- 

 logues do not contain 100. 



Prof. Aitken has examined, during this research, more 

 than 12,000 stars, and finds that the doubles discovered 

 form about 3 per cent, of this total. Including those pre- 

 viously discovered, the ratio of double stars, with distances 

 of less than 5", to the whole of the stars down to the ninth 

 magnitude is apparently i : 18 to i : 20. This ratio is not, 

 however, the same for all parts of the sky, for whilst in 

 some regions observed double stars are very scarce, in 

 others the ratio increases to about i : 8. 



Other details concerning the survey, its prosecution and 

 the reasons for carrying it out are given in Prof. Aitken's 

 interesting paper. 



Report of the Yale Observatory, igoo-4. — Dr. Elkin's 

 reports to the board of managers of the Yale University 

 Observatory for the years 1900-4, inclusive, occupy eight 

 pages, and briefly describe the large amount of work per- 

 formed at the observatory during that period. 



Heliometer observations are the chief feature of the 

 work and special attention has been paid to the deter- 

 mination of the parallaxes of stars having large proper 

 motions. Practically all the stars in the northern hemi- 

 sphere having known motions of o".5, or more, have now 

 been observed at Yale. A second triangulation of the 

 Pleiades and determinations of the parallax of Arcturus 

 have also been made. Another feature of the work is the 

 photography of meteor trails, and numerous trails of 

 meteors from the principal showers have been obtained. 



NO. 184 I, VOL. 71] 



PRIZE SUBJECTS OF THE BATAVIAN 

 SOCIETY OF EXPERIMENTAL PHILOSOPHY. 

 A T a recent general meeting of the Batavian Society 

 of Experimental Philosophy of Rotterdam the follow- 

 ing subjects were proposed for competition. The gold 

 medal of the society, of the weight of thirty ducats, or 

 its value, will be awarded for the best answer to one or 

 other of the suggested questions. Answers may be written 

 in the Dutch, French, English, German, or Latin 

 languages, in another handwriting than that of the com- 

 petitor, and must reach the secretary. Dr. G. T. W. 

 Bremer, at Rotterdam not later than February i, 1906. 



Chemistry. — .■\n experimental investigation of the atomic 

 weight of an element which has not yet been satisfactorily 

 fixed ; a research on the causes of departure from Ostwald's 

 dilution law ; measurements of the osmotic pressure in 

 solutions at concentrations corresponding with deviations 

 from the simple gas laws ; a study of the origin and 

 physiological significance of the green pigment in the 

 body of green articulated animals ; experiments elucidating 

 the formation and transformations of the sap in india- 

 rubber plants ; a re-investigation of the variations from 

 the laws of electrolytic dissociation observed by Kahlen- 

 berg in 1901 ; an explanation of the thallioquinic test for 

 quinine. 



Physics. — An investigation of the electrical properties 

 of some metallic alloys ; of the variation with temperature 

 of the specific heat of mercury ; of the specific heat of 

 sulphur and phosphorus in their various allotropic forms ; 

 of the indices of refraction of substances showing 

 anomalous dispersion; of the cause of phosphorescence, 

 particularly in the case of the lower organisms. 



Biology. — .^ description of the life-history and proper- 

 ties of one or several species of moulds, ferments, or 

 bacteria which are of industrial importance ; the action 

 of sulphur and of copper salts on plant parasites, and of 

 mineral salts on the development of fungi ; the role of 

 micro-organisms in the formation of humus in the soil. 



Physiology. — An investigation of the permeability of red 

 blood corpuscles to the ions of NaCl, NaNOj, Na^SO^ ; and 

 of the localisation of functions in the cerebellum. 



Geology. — .\n exposition of the theory of the origin of 

 the Netherlands ; a critical investigation of the volcanoes 

 of the East Indian Archipelago. 



Civil Engineering. — Statistical investigations of the 

 Dutch "polders"; or an investigation of one of the 

 principal rivers of Holland. 



r//E PIC DU MIDI OBSERVATORY. 

 T N a recent number of La Nature, M. L. Rudaux gave an 

 interesting account of the present condition and opera- 

 tions of this important mountain station. France is well 

 provided with high level stations, and the observations 

 from seven of them are published daily in the Bulletin 

 International of the French Meteorological Office. An 

 account of the very favourable position of the Pic du Midi 

 station, and of the almost insuperable difficulties experi- 

 enced by its original founder. General de Nansouty, was 

 given, in considerable detail, by .M. R. Radau, in his useful 

 little work on " Mountain Observatories " (Paris, 1876), 

 and has been summarised by Mr. A. L. Rotch in the 

 .imcrican Meteorological Journal. The summit, which has 

 an elevation of 2877 metres (the observatory being 17 

 metres lower), is situated on the outskirts of the Pyrenees, 

 in lat. 42° 56' N., and long. 2° 12' W. of Paris, and affords 

 one of the finest views in Europe. Towards the north an 

 immense plain stretches as far as the eye can see, and to 

 the north-west, on very clear days, the blue waters of the 

 Atlantic are visible, at a distance of 160 km. It lies 

 directly in the path of the great atmospheric disturbances 

 which traverse the Bay of Biscay, while the summit mostly 

 enjo\'s a clear and mmlnous atmosphere, being some 200 

 metres above the level at which thunderstorm clouds usually 

 gather. These advantages early attracted the attention of 

 astronomers and scientific men ; M. F. de Plantade died in 

 1741 while observing at the ridge which has since taken 

 his name. 



The project of a permanent meteorological station was 

 first mooted in 1869, and provisional observations were com- 



