July, 1906.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



469 



markable appearance on his photograph. Closely 

 east of the same star, a photograph taken by Barnard 

 shows some curiously shaped dark markings, which 

 seem to be openings through the Milky Way in this 

 region. On a photograph Ijy Max Wolf, of the region 

 near f Cygni, there is a remarkable black hole and 

 some smaller ones. 



The question naturally suggests itself, what is the 



some of the extracts quoted above will show. Photo- 

 graphs of the great " Coal Sack " near the Southern 

 Cross pro\e conclusively, I think, that the darkness 

 of this remarkable spot is due to a real paucity of stars 

 compared with the richness of the surrounding regions, 

 and probably the same thing is true of the other dark 

 spots in the Milky Way. We have really no evidence 

 of the existence of dark bodies in space. Professor 



The Milky Way round Ophiuchi. 



(PJio(o.|nij)/iiii h!l Prof. E. E. Biirnanl.) 



real nature of these curious black spots? Some as- 

 tronomers have suggested that they are due to mas.ses 

 of cooled down, or partially cooled down, nebulous mat- 

 ter which absorbs the light of stars behind them. 'Hie 

 term " hole," which I ha\e u.sed in the present p.iper 

 implies that my own view is that they are really holes 

 or openings through the regions of stars or 

 nebulous matter, and in this view'of the matter 1 am 

 sui^ported by the opinion of several astronomers, as 



Xewcomb thinks that there is probablv little or no ex- 

 tinction due to dark bodies, and he says, " We may 

 say with ceilainty that dark stars are not so numerous 

 as to cut olT any important part of the light from tlic 

 stars of the Milky Way, because, if they did, the latter 

 would not lx» so clearlv seen as it is. Since we have 

 reason to believe that the Milky Way comprises the 

 more distant stars of our system, we may feel fairly 

 confident that not much light can be cut oft bv dark 



