;oo 



NATURE 



[May II, 191 1 



outhtandtng qucstto' 

 ITk- lirst wa» thn t: 



lu.tiii: bcak-, wlmli. >1 ""t in th-v i.iiuinns on 



April 20, they have Id upon. J he si(oi)d was 



that of carrying the . ... i^. .jx ctrutn observations furth<r 

 into the ultra-violet, with the prosp<-t i of inrrcasinfj tli 

 vaUu-s ol ihi- ((iiisl.iiit pr-viousK ;i'u'n, ;iiu! this ha- nnv. 

 lxM?n ^ 



rffjton 



;.;d ill th^: IVJi-i.S-O ob'.' rv.ili"; .;i. . l.il 



.11 shows that there is no ntM.-d v.iluc 



..I III-- vcjar constant obtained ^■- ''" ■' ' '"ih- 



iished ((KtVirients of atmosph< : 



.11-.. huu.\.l'. .ill .lliout \X l)i-i 



witliii 

 b« aci 



■;i di-xj-> not .ipix'.'ir to 

 she results obtained at 



.i.:i:,,. ,,f 1I,;. ,•,■■;.. ^ 



niinute, 

 :i'' nio»it 



\ aluahle aiM;; ;.mi - ;.. . 

 atmospheric di-iinh.nn 

 systematic -'i.i .t 1! 

 prominent 

 in No. .!, 



variation 

 majjnitudi 



i.Iii .\\ 11 ol;.- II I ii.!i;; I II.- ^illl S 



an- likely to ai i rue from the 

 -pe( trohcliugranis sho\viii<:; .solar 

 of such a study are puhli'-I: 

 l]]c Astrophysical Joitnuil 

 ■■ ^ \ R, 1;. Smith, who h;ive rediu. d 



•h. liu^iams taken at the Moiini 

 W il-on Dbservatory, and compar. d the prominences with 

 those shown on photographs tak. n at tln' Ycrkes Observa- 

 tory and with those observed \i>u.ill\ at Catania. The 

 eompari^oii of th.' ]\a and tli.' c.alriuni-li.Ljhl photographs 

 j)i/cr .ST and with the Cat.ini.-i hvdroe.n observations 

 reveals several points of interest. Aniorii:; these it would 

 appear that the calcium vapours ris.- to er, at.r heights 

 than those of hydrogen, a feature shown both in the 

 measures of heights and of areas. The mean height 

 (;*''> r f ''t,-^ Mount Wilson calcium prominences is about 

 7 han the mean height of the hydrogen promin- 



eii rverl there and at Catania. It would also appear 



that the calcium prominences h.av. ,1 slieiitly different dis- 

 tribution from rhose of hydroi^en. Results for the period 

 too6— 8 are t.ilnilated and plotted, and one or 'al 



cases of interrelati(Mi with disturbed areas are 



The Move.\ient of St..\rs of the Orion Type. — In a 

 paper published in the Bulletin dc I'Acad. roy. de Belgique 

 in 1910, Dr. Stroobaut directed attention to the different 

 values obtained for the sun's velocity through space when 

 it was derived from the radial velocities of Orion stars 

 from when it was derived from the velocities of other 

 stars; since then Profs. Frost and Kapteyn, using different 

 coordinates for the apex, have disclosed a similar differ- 

 ence. Dr. Stroobaut has recalculated his values with their 

 value for the apex, and finds that his new results show 

 pr.ictically the same difference as theirs. He obtains for 

 the solar velocity 19-25 km. when using all stars, and 

 21-8 km. for the Orion-type stars; the latt. r is divided into 

 i6-o km. in the region of the apex and 20-2 km. near 

 the antapex (/>i(//. dr VAcnd. roy. de Brlt^iqur. No. i, 

 P- 30)- 



Ij'iikmekis I or Encke's Comet ne.\r Perihelion, iqii. 

 — In No. ",9 of the Mittcilungcn dr.r Nikolai-Haiiptstirn- 

 'varte su Pulkowo Dr. Backlund discusses the orbit of 

 Encke's comet during recent years, and tabulates the 

 several perturbations it has suffered since its apparition 

 in 1898 ; these are very small. He also gives a revised 

 set of elements, from which he has prepared an ephemeris 

 covering the period of perihelion passage and extending 

 from July i to September 21 ; the return is not a favour- 

 able one for observations. 



The Cat.\ni.\ Observations of Sun-spots and Facul.*:, 

 1910. — Prof. Ricco's annual tabulated summary {1910^ of 

 the spots and faculae observed at the Catania bbsenatorv 

 appears in No. 3, vol. xl., of the Memorie di Astrofisica 



NO. 2167, VOL. 86] 



'■d Aslronomia. The v'aluea for the year »how • 

 ■.olar activity it »till declining. Th« m^sin daily i 

 of spots was 17, and on 

 w*!rc recorded. 



I III: /■•'»'■ 



'riii. k..>.o . 



exhibition 

 yc.'ir, .and in the 

 hridK 

 dav . 



PHOTOCRAI""r ••nrrF' '■ 

 KX HI BIT Jo 



igr.'iphic '^i 



the spring 



I! of t!,. P, 



now ano 

 Mexandra I. 



\tn,n of hej lAvn photograph.s, and surround. 

 I is a very large collection of portraits of K 

 i.iiw.im \ II. .As these date from about 1853, t' 

 be studied both as a pictorial history of our late K 

 .ilso as representative of the development of »!', 

 |)ortraiture from the early days of the co' 

 ilntomologists and mirrnsrnpists will he pli 

 tine portrait of Mr ' 

 same galh ry. 



■ 'ere is a lar^e coiii(i:on <ji .iu' 

 .imong them colour transparei 



indicate 

 cesses f 

 and ■' 



Ih.v 



ili.ii til. 



.r tl:.- p' 



avlirrht they are 

 mnnber of those 



. ii.u'f.Tphv of fOlo- 



more successful than 

 W. J. Ilerschel and 

 -how pliotographs of rainbows, which 

 om the poor representations that the 



I . photography can render of them. There 



is some iioia!>le pliotomicrographic work in colour, especi- 

 ally various minerals and crystals shown between croswd 

 Nicols, and .imone Prof. Wnyinouth Reid's collection there 

 are a few examples of high-power pathological work. 



The f.rTer.il n.itur.il history section is not very extensive, 

 but includ.s s- v. r.d " life-histories " of moths, butterflies, 

 tadpoh s, and. by Mr. William Farren, a series of twelve 

 prints illustrating the nesting period of th« nightjar. The 

 " Great American Epfret," bv Mr. Hutrh C. Knowlcs, and 

 " Cannot going- down wind." bv Mr. Oliver G. Pike, are of 

 special interest at the present time. 



The scientific section is larger than it has been lately. 

 This branch of the subject can never be adequately repre- 

 sented, because only a small proportion of the scientific 

 work done is suitable for an exhibition, but this year the 

 societv has been successful in getting together an excellent 

 collection. High-power photomicrography is well repre- 

 sented. Dr. T. W. Butcher's Navicula Smithii and Coscino- 

 discus astcromphahis. and Dr. Duncan J. Reid's Trypano- 

 somes are speciallv noteworthv. Mr, Charles R. Darling 

 shows a series of photographs of drop formation taken 

 comparatively slowly, with exposures of one-tenth of a 

 second inste.^d of. as heretofore, in a few millionths of a 

 second. The drops are of aniline oil in water. Among the 

 radiographs, the series by Dr. Thurston Holland represents 

 probablv the finest work at present possible in this direc- 

 tion. Ten lantern slides of a normal stomach, taken by 

 Dr. F. Haenisch with a Rcentgen-cinematographic ap- 

 paratus, show- the peristaltic wave moving down the great 

 curvature. Prof. Zeeman contributes an illustration of his 

 recent work on the effects of a mag^netic field on the 

 absorption sodium spectrum lines, and Prof. R. W. Wood 

 sends some of his photograohs of landscapes taken with the 

 infra-red radiations. Dr. George H. Rodman shows photo- 

 micrographs of the pollen cells of fiftv different flowers, and 

 also a series of stereo-photomicrographs of natural histor\- 

 and botanical subiects, which represent some small objects, 

 such as diatoms, in a realistic wav that is very rarely seen. 



.Amonpf the astronomical exhibits that will be studied with 

 interest are fiftv transparencies bv Dr. Max Wolf, of 

 Heidelberg, of various comets and nebulre with their 

 spectra, photographed under different optical conditions, and 

 an extensive series of photographs of planets and comets 

 and their spectra, lent by the Lowell Obser\-atory. Of the 

 many other noteworthy subiects we can only refer to illus- 

 trations of rotary photogravure in its applications to news- 

 paper illustration and three-colour printing, shown by 

 Mr. A. J. Newton, the principal of the London County 

 Council School of Photo-encraving. 



