Marvels of the Universe 



rise like smoke-wreaths in summer, or float like clouds high above the solar surface, but are often 

 connected with it by narrow stems or pillars. The eruptive prominences often show the lines of 

 many metals in their spectra — of iron, sodium, magnesium, titanium, etc., and are subject to 

 changes and movements of the most violent nature. Thus a group, sketched by M. Fenyi on 

 September 30th, 1895, went through numerous changes in a very short time. The greatest 

 height attained was more than three hundred thousand miles — about forty times the diameter 

 of the earth, or considerably more than its distance from the moon. During four minutes of the 

 time that it was being watched it increased in height nearly one hundred thousand miles, an 

 upward motion of some two hundred and seventy-eight miles per second. After this violent 

 development it faded and disappeared almost as quickly. 



The solar " flames " are not isolated features of the sun : they form an intimate part of the 



solar organism, having a close 

 connection with the spots of 

 the general surface, lying be- 

 low them, and with the corona 

 rising above them. From time 

 to time they give indications 

 of a connection with the 

 general structure of the sun 

 more intimate still. Thus on 

 June 26th, 1885, M. Trouvelot 

 saw two huge prominences, 

 each more than three hundred 

 and fifty thousand miles in 

 height, rising from the sun. 

 Flames of such dimensions are 

 exceedingly rare ; it therefore 

 makes it rnore significant that 

 they rose exactly opposite to 

 each other, from the ends of 

 the same diameter. In cases 

 like these we may be sure that 

 the origin of such tremendous 

 energy does not lie in the mere 



ENORMOUS ERUPTIONS ON THE SUN. ^j^gU ^^ ^^^.j^^^ ^j ^^^ g^^_ ^^^ 



These great prominences consist of flame rising sometimes to a height of over three 



hundred thousand miles, which is about forty times the diameter of the earth. I"-! Qcepcr. 



THE X-RAY SPIDER 



BY R. I. POCOCK, F.R.S. 



In the late summer and early autumn our bushes and hedgerows are decorated with the wonderful 

 orbicular webs, consisting of radiating and concentric threads, which are spun by a large fat-bodied 

 spider, known from the white pattern on its back as the Diadem or Cross-Spider. Spiders related 

 to this species are very abundant in the tropics, where they attain far larger dimensions than our 

 British examples. One of the finest, both in colour and size, is the kind known as Argiope, all the 

 species of which have lustrous, silvery-white backs and a mottled underside. They spin the same 

 kind of web as the Diadem spider, but many of them decorate the centre with broad white ribbons 

 of closely-woven silk, the arrangement of which differs according to the species. In the web of 



