NEBULOUS MILKY WAY. 141 



the polishing slate of Bilin contains, according to Ehren- 

 berg, 40000 millions of the siliceous shells of Galionellee. 



Nearly at right angles to the Milky Way formed of stars, 

 in which, as Argelander remarks, brilliant stars are more 

 numerous than in any other part of the heavens, there is 

 another milky way consisting of nebulse. The first of these, 

 or the galaxy of stars, according to Sir John Herschel's 

 views, forms around our sidereal system, and at some dis- 

 tance from it, a detached ring or zone, similar to the ring 

 of Saturn. The situation of our planetary system is 

 eccentric, nearer to the region of the Cross than to the 

 opposite region, that of Cassiopea( ul ). In a nebula 

 discovered by Messier, but which has been only imper- 

 fectly seen, we seem to discover the image of our own 

 sidereal system, and the divided ring of our Milky Way 

 reflected, as it were, with wonderful similarity ( 112 ). The 

 galaxy of nebulse does not belong to our sidereal zone, but 

 surrounds it at a vast distance, and without any physical 

 connection, passing almost in a great circle through the 

 nebulse in Virgo (which are particularly numerous in the 

 northern wing), through the Coma Berenicis, the Ursa 

 Major, the girdle of Andromeda, and the Northern Fish. 

 It probably intersects the galaxy of stars in Cassiopea, and 

 connects the poles, which are situated where the thickness 

 of the stratum is least, and which are poor in stars, owing 

 possibly to the action of those forces which have formed the 

 stars into groups ( 113 ). 



It follows from these considerations, that our sidereal 

 cluster which, in its projecting branches, shews traces of 

 great progressive changes of form is surrounded by two 

 rings, one of which, the Nebulous Milky Way, is very 



