1 66 



NATURE 



[March 30, 19 11 



un the registration 



.->i.i...-i.. ., v,; A. ..■..*.».. ........,;......., to \vi> :. 11 r<-lr!.n(.- was 



made in these columns on March 33 (v 



Ii-iuls to certain inI»Tcsfiiiji (ornparison 



imivi'isir:. 'irohneiU l .iiitcr 



ul i(,i(. 1 . iilents, as .■;.407 



till- Willi. 1 b' ling the pa^i iivi- years 



hiMii an iiiM. iration of no fewer than 



i.:,.|,.- ^ludrnls. '! Ill- ,.,,..,., of Woitvn sni'l-nlK \->-\'i 



^rowii fi'oin Jil \\\'- \i:irs a^^o In .'.)i^ in ' 

 sr-,sion. Till- niiml»r <•( stinl.iil-, ^Iml-. iiil; i>in. 

 7()i.l a-^ (()iii|).ii . (1 uilli 7;-|'i iii 'li'' |i)'\:"U-. ^ --...;,, ill 

 af^riruUiin- j.v(Ii a> <niiipai..l willi -'I'^S. ■""' fi'i'--'i> '7' 

 as compared wiih i.'m. Ih' ihi.- In;;''-! iiiii\ .-rsities 

 — lierlin, Miinihrn, and l..i]./iL; ..l..n. .r,inll.(l no fewer 

 than 30 P'f cent, ol Ih'- loial (..riuaii student body. 

 ncrlin niiiains at the lop wiih an enrohnent of 9686 

 studiiiis. as at'ainst 0242 last wiiitrr. This is followed by 

 ihi I ni, Miincli' n with (mju^ sfudfiits (''5S7 last 



\ .III. !■ 1.11 ciiiliiird thai for tin- iirst liiin' in 



\ il .\:iiorican universities the 7000 mark was 

 til. list winter session, Columbia having a grand 

 ioin <ii 7.) M siiidonts. Six American universities have 

 now nioir than 5000 students. In Germany, Leipzig is 

 till' third most luimerouslv attended university, and has 

 .(Mi>o siiid. nts, Ivuiii fellows with 3846. Seven others 

 h.i\i- frwi r than iooo and iiion- than 2000 students, and 

 all but two — Greifswald and Rostock — have more than 

 1000 students. The figures show that all the universities, 

 with the exception of Erlangen, ^^'iirzburg, and Giessen, 

 have increased their attendance, the largest gains having 

 been iiinde by Hnlle. Kiel, Jen.i, Tiihingcn, and Rostock. 

 Sim .' KidM III iM'esl.au lias In en passi'd by Halle, Gottingen 

 h\- l"reilniri:j, IIi'idclhiMj.^ by Miinster, Wurzburg and 

 Konigsberg by Kiel. In addition to the 54,822 matricu- 

 lated students, 3528 men and 1772 women are enrolled as 

 auditors, giving a total of 60,122 individuals receiving 

 instruction at the German universities, the largest number 

 in the history of German higher education. 



SOCIETIES AND ACADEMIES. 



Lo.NnoN. 



Royal Society, March 23.— Sir Archibald Geikie, K.C.B., 

 president, in the chair. — G N. Watson : A theory of 

 asymptotic series. — R. T. Beatty : The ionisation of heavy 

 gases by X-rays. — W. Wilson : The variation of the 

 ionisation with velocity for the $ particles. Rays of 

 dilTerent speeds were separated, by means of a magnetic 

 field, from the heterogeneous beam given out by the active 

 deposit from radium. The relative numbers of particles 

 corresponding to the different speeds were determined by 

 measuring the charges gained per second by an insulated 

 copper vessel which was placed in the path of the rays, 

 and was thick enough to absorb them completely. The 

 corresp>onding ionisations were determined by a 'separate 

 experiment, and were corrected for scattering of the rays 

 by the walls of the ionisation vessel. The results obtained 

 are as follows : — (i) The ionisation produced per cm. by 

 $ particles in free air varies inversely as the square of the 

 velocity, between the limits examined. (2) The ionisation 

 in a thick copper vessel is not connected with the velocity 

 by any simple law, but can be approximately represented 

 by l = kic—v), where I is the ionisation, v the velocity of 

 the particles, and 7c and c constants. — C. G. Douglas and 

 Dr. J. S. Haldane : The causes of absorption of oxvgen 

 by the lungs in man. — Prof. Arthur Schuster : 'The 

 influence of planets on the formation of sun-spots. In 

 this investigation the relative position in heliocentric longi- 

 tude of_ a planet, and that point of the sun's disc where 

 a spot is first observed, is taken as starting point. Spots 

 first noticed within 60° of the eastern limb were excluded 

 on account of the possibility or probability that these spots 

 were formed in the invisible hemisphere, and only brought 

 into view by the rotation. The total number' of spots 

 1 ^"j !"*<> account was about 4250. Imagine an observer 

 placed on the sun. He might observe within each solar 

 rotation, imagined to be divided into twentv-four hours, a 

 p^Ianet rising, reaching a maximum altitude, called 

 planetary noon," descending and setting. The chief 

 results of the investigation, dealing with the planets 

 NO. 2 161, VOL. 86] 



Mercury, Venus, and Jupiter, are as f<rflows : — (i) .More 

 spots are forrr>ed when the planet is above the horizon than 

 during the planetary night. The excess amounts to 45 per 

 cent, in th»; case of Mercury, 64 per cent, in the case of 

 Venus, and 1-5 per cent, in the case of Jupiter. The 

 probability that this excess is accidental in the case of 



Mercury and Venus is about i in 7 ard • •" - ctivcly. 



In till' case of Jupiter, the diflerii than 



iniglii be expected by the theory oi • much 



importance is attached to each of these- results taken 

 separately, but if the theory of probability be applied to 

 ih d results, an accidental coincidence of the 



e me hemisphere over the other to the amounts 



iiuiiLiiiiu will not happen more than once in 1150 cases. 

 (2) More decided results are obtained if the formation of 

 spots during different parts of the planetary day are 

 investigated. If the distribution were purely accidental, 

 twice as many spots should form during the eight hours 

 after the planet has risen as in the four hours before it 

 sets. It is found, on the contrary, that during the latter 

 interval the number of spots bears a proportion of 0344, 

 0349, and 0-347 respectively to the whole instead of 0-333, 

 the planets always being taken in order of distance from 

 the sun. The average excess here amounts to about 5 per 

 cent. (3) The effect of the planets when compared in 

 detail exhibits remarkable similarities. At an observing 

 station on the sun, a strong minimum of spot formation is 

 found to exist shortly before the planet rises ; this is 

 fallowed by a decided maximum in all three cases one 

 hour after the rise. This is succeeded by a drop in 

 activity, leading to a minimum, which occurs sooner with 

 Mercury and Venus than with Jupiter, but this distinction 

 may be accidental. The most remarkable feature in all 

 three cases is the rapid rise from a secondary minimum, 

 one hour after the planetary noon, to a pronounced maxi- 

 mum two hours later. This is followed by a drop lasting 

 until the hour before the planet sets. The action after 

 that and during the greater part of the planetary night is 

 irregular, and might disappear if a larger quantity of 

 material were available. The probability that all three 

 planets should show their greatest activity at the same 

 hour to the extent shown by the figures is i part in 130 

 million. The probability of the corresponding minimum 

 in the planetary morning is not much less, so that taking 

 the coincidence of both these factors into account, we may 

 exclude the possibility of an accidental coincidence. 



Royal Astronomical Society, March 10. — Mr. F. W, 

 Dyson, F.R.S., president, in the chair. — Mr. Stratton 

 gave an account of a paper by the late Mr. Bryan 

 Cookson, a research on the aberration constant and the 

 variation of latitude by means of the floating zenith tele^ 

 scope. The paper was left unfinished owing to the illness 

 and death of the author, and had been completed and 

 prepared for publication by Messrs. Hinks and Stratton. 

 Their principal work had been to renew the search for 

 systematic errors, and to prepare for press an account of 

 the investigation. Sir David Gill spoke of the value of 

 the constant of aberration obtained by Mr. Cookson. In 

 reference to unexplained discordances, he suggested the 

 possibility of a displacement of the zenith from meteor- 

 ological causes. — Mr. Eddington gave a short account of a 

 paper by Dr. W. de Sitter on the bearing of the principle 

 of relativity in gravitational astronomy. It was assumed 

 that mass or inertia had an electrical origin, and it had 

 been shown that the motion of matter relatively to the 

 aether is impossible, the author being of opinion that the 

 .Tcther hypothesis might be abandoned. — Mr. Davidson 

 showed photographs of Jupiter's satellite VIII.. taken at 

 the HelwSn Observatory, Egypt, when the planet was too 

 far south for observation at Greenwich. There was a 

 certain residual when compared with theory which might 

 disappear if we assumed a small error in the tabular orbit. 

 — Prof. Turner read a paper on the determination of the 

 positions of reference stars and fundamental stars by 

 photographic processes. He compared the superseding of 

 visual by photographic observations to the substitution of 

 the telescc^e for the old "sight" instruments, which 

 Hevelius and Halley considered the most accurate. Sir 

 David Gill pointed out difficulties and recommended 

 caution, and the Astronomer Royal considered that photo- 

 graphy could not render observations with the transit 

 instrument unnecessary, though moving wires might be 



