378 



KNOWLEDGE • 



[Nov. 3, 1882. 



a»troi»-«u;?rs Lave the power of oliserviiig at one scasou of 

 thf \ . ..r ;h. acivaiuiiijf side of the sun, aritl six inoutlis 

 la;. .; side ; Olid they iiii;;ht fairly exjH'ct that 



r, _ ii c'jijHwite processes are at work on so 



._;:_ uld present a very ditlerent appearance, 



i; .r yet reco_i,'nis<Hl the sliglitest difl'ercnce 



1. ; .vhi-re the sun is, as it were, shovelling 



ii. .:irils the earth during the spring of the 



I. • If I and tlio other side where ho is 



t!, :. i-s. Both sides look exactly alike. 



1 feature of Mr. Williams's theory which 

 he >)'>!.!. . .1. iviids against criticisms of mine. I liad 

 object.-d tJiut bodies travelling round the sun could never 

 lukve c»>uie into existence as a result of ejections from the 

 sun. GrauteJ, says Mr. Williams (though tlint was not 

 exactly the way he put it in "The Fuel of the Sun," 

 I think), if there were only simple ejections, but if, 

 after matter has been ejected, it explodes like a rocket, 

 " pretty generally all round," a ring of meteors might 

 U formed; and lie cites the behaviour of the coloured 

 prominences of the sun as showing tliat this actually 

 happens. It is true they often, after shooting up from 

 the sun's surface, expand laterally, but there is nothing in 

 this more tlian v»-e see in every case iu which gaseous 

 matter is shot tlirough a region of high pressure into a 

 region of low pressure. That matter .shot to a height of say 

 70,000 uiilesfrom the sun's surface, should there explode late- 

 rally, >o as thenceforward to circle around him, the matter 

 exploding must divide itself into opposite portions, each 

 travelling from the point of explosion with a velocity of 

 more than L'40 miles per second. Nothing of this sort, or 

 approaching anywhere near this, has ever been seen, ilore- 

 over, wliat is tliere except expansive action to produce 

 lateral motion at all in the ejected gases 1 and how can 

 lateral expansion do more than extend the expanding 

 matt<-r until its density is equal to that of the atmosphere 

 around it at the sainc level 1 In the case of t<^rrestrial 

 liomlf-rockets there is an enclosing case which holds the 

 explosive substance until, on ignition, the gases are formed 

 which, by their exj<ansive action, drive out the particles of 

 matter which form the luminous display. The circum- 

 stono-s are therefore favourable to the forcible expulsion 

 of niatu-r. It is diflerent in the ca.se of the gaseous matter 

 cxp«-lli-<l from the sun, when the outrush is over. For the 

 globing gas driven violently outwards on these occasions 

 is not enclosed in anyway. It is simply (as the spectro- 

 s<x>{« khows) driven up as a stream of dense gas in a rela- 

 tively rare atmosphere ; and as soon as it can (which is 

 g-nerally not before it reaches a higher and still rorer 

 atcuotiphere) it expands lat^rrally. There is nothing ex- 

 plo*iv>- ul<out this action, any more than there is in the 

 lateral ('Xi^ansion of cumulus clouds, or (which more nearly 

 illuktruti-ji the caw,-) in the outspread of cloud above a 

 volcano afttr each outburst of the gases which had been 

 imir: ...l v,;ti,in. If there were the enormous lateral 

 V' ■ 1 by Mr. Williams's theory, the spectro- 



» ere this have revealed them ; but while 



it . iience of cyclones low down in the solar 



atii... J !;• f , ui -hown by motions towards ond from the 

 eye at the tun's edge, it has never shown any trace of 

 ■uch nioliona in tlie glowing gas flung high aliove the sun's 

 kurf«c<!. 



T»i<-r»! i-t, however, much tliat is well worth studying in 

 Mr. Wiltianis'ii reasoning. Ilin conclusions seem to me, for 

 tl»e m'.st port, quite erroneous, Init the evidence he 

 quot<,-<t in their favour is dcaerving of the most careful 

 ezaojination. 



Mr. Willianu coiuiderii that hi« views have been and 

 ar« being adopted by other writers on astronomical and 



physical matters, " without corresponding acknowledg- 

 ment " ; and he tells us that in due time "an appendix to 

 the ' Fuel of the Sun ' " will bo published (to a new edition, 

 I trust), giving the particulars of such adoption. 1 doubt 

 the wisdoni of this. These <iucstions of priority are fit 

 only to occupy very small minds ; and I am sure Mr. Wil- 

 liams agrees with me in regarding all egotism as silly : — 

 even the appearance of it is a thing to be avoiiled. But 

 if he does what he proposes, ho will lm\ e to be careful lest 

 peradventure he should lind the boot unmistakably on the 

 other leg. He has a clear case against Dr. Siemens, though 

 I feel well assureil Dr. Siemtuis was not aware, when he 

 l)ublished his theory, how fully all that was sound in it, 

 and a great deal also that is unsound, had lieen anticipated 

 by i\lr. Williams. But in some other cases, where he hints 

 a suspicion that his views have been adopted without ac- 

 knowledgment, he will lind priority {itihal (judiiliitii valere. 

 dcbvt, which is not saying nmch) with others. For instance, 

 the theory that the larger ]>lanets are miniature suns, " sur- 

 rounded by a sphere of vaj)Our, the outside of which we 

 see," he includes among his startling conclusions, "utterly 

 at variance with general astronomical opinion when he 

 reached them." When he rcarhrd them I do not know, 

 but I do know when he published them ; and 1 know that 

 several months before, in the winter of 18G9, 1 advanced 

 that theory in a series of lectures deli\ered at the Koyal 

 Institution, Manchester (in the syllabus of which the theory 

 was stati'd in so many woi'ds), while for at least a year before 

 that, the probably intensely-heated condition of the giant 

 planets had be(-n dealt with in the MS. of the work after- 

 wards published under the title of " Other Worlds than 

 Ours." Air. Williams could not be expected to know about 

 the Manchester lectures, but ho must know enough of the 

 conditions under which books are published to be well 

 aware that the chapters on the giant planets in the middle 

 of that work were written, and even in type, before his 

 " Fuel of the Sun " was published. The theory was an- 

 nounced by me long before. Not that it matters in the 

 least, only : if such questions an: to be raised, we may as 

 well raise them by the right end. 



THE DOOM El > COMET.* 



Tuis little pamphlet, price sixpence only, gives a good 

 deal of interesting information about cometic astronomy. 

 It deals chiefly, in the first part, with the comet now 

 shining so conspicuously (when the weather is clear) in our 

 morning skies. In the second part, it discusses the possible 

 efll'cts of the comet's absorption by the sun ; and, in pass- 

 ing, criticises the theory of sun-spot influences with an 

 engaging frankness which we fear will prove somewhat dis- 

 ta.steful to the believers in that theory. Mr. Oliver arrives 

 at the conclusion that there will be "slightly intensified 

 metiorological plutnouK'na," whenever the comet is ab- 

 sorbed. He believes that the British Isles will be affected 

 in "a way such as to induce warmer and drier weather, or 

 in other words, good seasoim," opposite conditions prevail- 

 ing (with important local variations, however) in Eastern 

 Europe, India, Australia, and North America. We (the 

 Editor) wished we knew enough to guess a tenth of what 

 Mr. Oliver seems somehow to know. Mr. Oliver says, V)y- 

 the-way, that we have twice misled the public on the 

 subject of this comet. We doubt if we have misled them 

 once. What we said erroneously in Knowledge of Oct C 

 was corrected in five daily papitrs, having an aggregate cir- 

 culation of halfa-million, on the morning of Oct. 7. As 



• Tlii hunmed Comet and the. Wnrld'n Knil. ])y J. A. Wk«TW()OIi 

 Olivkii. (Wyman k Hong, bondon.) 



