204 



NATURE 



[June 2;, 1895 



THE SUN'S PLACE IN NATURE} 



VII. 



AT the end of the last lecture, mmul iMilence was brcmghl 

 "^ forward which leads to the cvuicUision that in those stars in 

 the spectrum of which bright lines arc seen, we arc dealing with 

 bodies closely associated with nebulx-. It was at once suggested 



Ki... .-.j. I.ifihl-curvc of.Mi;..!. 



tli.i! |>.>-iiM\ lj\ ilioie nu« nielhiMi^ of in(|iiiry to which I have 

 already referred, we might be enabled to' demonstrate the 

 existence of the nebuhe, although we can never hoi>e to 



see them by the unaided human eye 

 to me that long exjiosed |>hotograph> 

 surrounded by nebulx. So I wrote 

 to Dr. Koljerls, who always kindly 

 places himself at the dis|x>sal of any 

 student, and a,skecl him if he would 

 l>e sf) g(K)d .Ts to photograph that re- 

 gion of the heavens in which most of 

 the bright-line .stars have l>een ob- 

 .served. Me at once acceded to my 

 retjuesl, an<l took |>hotographs, .is 

 <lcsired. with his in.slnnnent, giving an 

 •ex|>')sure ofthreeanda quarter hours. 

 The result a little <lisap|viinted me. 

 l)ecau.sc he re|X)rled that there w;is no 

 inilication whatever of any nebulosity 

 surrounding these stars. I'o.ssibly it 

 was on this account that Dr. Muggins 

 felt hiin.wlf justified in objecting to the 

 view which associ.-ited thew: .stars with 

 nebulous surroundings. But that is noi 

 the whole story. .Some time aflerwanls. 

 al the rcjuest of Mr. Kspin. Dr. Max 

 Wolf, who has an instrument which 

 is even more comgietent to pick up 

 faint nebula: than the wonderful tele- 

 scojK- i-mployc<l by Dr. Koljcrts, 

 ■•' ' I liotographs of this same 



' I need not tell you thai, 



to carry the inipiiry .-is 



The 



niii,'hl 



idea 



L:i\e 



occurred 



us si. Us 



is the most competent to give a verdict upon such inquiries as 

 this. Here, in the first instance, we have a photograjih of the 

 region surrounding the brightest star in the constellation Cygnus. 

 and you will observe that we have here and there indications 

 of nebulous matter as well as of stars. That is rendered evident 

 by the fact that in certain other regions we get a perfectly flat 

 background, whilst in this the background itself is luminous. 

 Now we come to the region in which 

 I hese bright 1 inc .stars have been recordci I 

 lor several years, and you see itisalnmsl 

 inipossibletopoint out in this phot(\graph 

 .1 large area in which there is not a 

 most obvious indicatitm of tliis luminous 

 nebulosity. Patches here and there 

 ^eem to indicate that the great difteren- 

 liation between this i>art of the sky and 

 others, lies not in the wealth of stars, 

 but in the wealth of the luminosity in 

 which they are situated. 



It was obvious therefore. fr^)m this 

 experiment, thai 1 w.as perferlly justi 

 fied in stating that these brii;ht line 

 stars were associated with nebuhe. 

 since we find the statement maile on 

 theoretical grounds now backed up by 

 these extjuisite data, which indicate 

 that most certainly there is a complete 

 association of nebulous matter willi 

 these stars. 



I do not want to part with that dia- 

 i;ram imtil I have pointed out to you 

 ihe enormous advanl.ige students of 

 science now ha\e in possessing such 

 magnificent photographs as these. Not 

 only is the wealth ^>f science rendered 

 obvious, but the wealth of nature. 

 Here, you see, is what modern science 

 makes of a little patch of the sky on 

 w liich the naked eye sees nothing ai all. 



Ihe conclusion is therefore this: there seems to lie no doubt 

 thai bright-line stars are directly connected with nebulous 

 nutter. I am glad to .add that this is also the conclusion of the 

 Aincilcui aslr■■rlolln■^^ wlv. Ii:i\i innuiml inl" tin- -iibiisl. 



I.' 



far as he could, he made the exjxjsure 



what Hc should consider almost im- 



jit^sibly long— s<i hmg, in fact, that 



one whole night was not sufficienl. 



Il's fi' ■ ' ■ 'h of this rcgiim was exposed lor thirteen hours 



^•n Ih' he next one was exposed fi»r eleven hours. 



Now I i,n the screen the result which wiis obtained 



Jjy Dr. Wolf With the instrument which at the present monicnl 



fa cotirtc of l,ecturc« to Workinx Men 

 "KV durinic Novcmlwr .-inO I >cccmlK;r, 



' Krvucd from shnr-' 

 at the MuAcum of I 

 1B94. (Continued fr ' 



NO. 1339, vol.. 52] 



I he m\i pMiiii III Ihe iiu-lciiiilir hypniliesis that some ol ihe 

 heavenly bodies are increasing, others diminishing their tempera- 

 lure -is one which 1 have brought out in Ihat strong form, but I 

 do not propose to say very imich about it to-night. Vou 

 may remember what has been said with reference to the h)po- 

 thesis of Kant and Laplace, and especially Laplace's \iew 

 that in the nebuhe we have to deal, as also in the stars 



