Tribune Extras Pamphlet Series. 



of hydrogen, and there you see it gradually returu- 

 ing to a position of rest. 



FRUPTTON PROMINENCES. 



Pcoo-il stage of proiniuence observed by Ziillner at lib. 20ni., Any. 

 20, 18C9. 



One thingon tins subject is very suggestive, tnoufrn 

 its true meaning is yet to be discovered. The spots 

 on the sun are arranged in two zones, and these cor- 



espoiul with the temperate zones on the earth. Ii 

 ^8 in these zones that the largest spots appear, and 

 rpoisare never seen far outside these zones. In 

 *ho other parts of the sun's surface we have a 

 gradual spreading out of this ruddy matter, as if 

 yon should pour an oily liquid into water or other 

 matter of a slis/Mly diH<>rent density. You see that 

 matter spreading through the water. It is matter 

 of one kind of density spreading through another. 

 In the region outside of the spouting zone it is as it 

 this hydrogen were floating about, finding its own 

 level. The prominences are in many cases 80,000, in 

 one case 200.000 miles in hight. Ten globes such as 

 this earth might ho piled one on the other, and only 

 reach the higlit of one of these. We have manifest 

 evidence th.it t here is really an eruptive activity in 

 these spouting zones. In this picture yon see how 

 there was a real erjpticn, propelling something un- 



<cen. and carrying g'JzztsVLL&k away from the sun 



SOI.AR OUTUrilST. 



Rnrr<"Rivf ptntos of nn ernpllon on tlio unn'i surface, oliarrved by 

 Pr..f. fnai I "I liMrfm.nlli Collie, 8ept. 7, 1N71. 



Thelirst \ii-\\ shows what Prof. Young calls a long 

 .w-lymg eloud of glowing hydroguu. only at the 



insignificant hight of about 20,000 miles. He was 

 away about half an hour, and when he came back 

 the cloud had vanished aud nothing was left except 

 these small bright fragments, and these fragments 

 were being carried up. They were carried to 

 a hight of 200,000 miles, and the rate was such 

 that, taking due account for alltne circumstances, 

 there must have been a propulsion of matter from 

 the sun at the rate of 500 miles per second. There is 

 no doubt that there are motions of 100 or 120 miles per 

 second, but thia matter, accoiding to calculation 

 was carried up at the rate of 500 miles per second. 

 A velocity of 380 miles per second would have been 

 enough to carry it away from the sun forever. The 

 greatest force which the sun can exert, either in 

 attraction or propulsion, is 380 miles per second ; 

 anything greater than that will never come back. 

 Now this was 500 miles per second; not, as I conceive, 

 of glowing hydrogen alone, but disturbed matter 

 coming from a lower stratum. Why should this 

 matter have been invisible ? If it had been from 

 the interior of the sun, it would have given a con- 

 tinuous spectrum; no lines could be shown by a 

 glowing mass; it would give a rainbow-tinted 

 streak. But wo have the evidence of the carrying 

 out of something from the sun. Now this must have 

 been a solid or liquid mass of great density, rifting 

 its way through the hydrogen gas. and being car- 

 ried outwards and onwards through Gpace. What 

 could it have been ? If the sun is thus at times giv- 

 ing forth matter, what becomes of it? Our earth 

 may possibly be exposed to that matter coming from 

 the sun. On this point I shall have more to say in 

 niy lecture on comets and ineieors. 



RAPI.V110N OP THE CORO" 



From a i)hoto*ruj>li mml" unrinj ihe solar ecUp 



