PORTION OF THE COSMOS. NEBULAE. 239 



from the Milky Way ; such in the northern hemisphere are 

 the regions of Yirgo and Pisces. It is true that the great 

 irregular nebulous mass in the sword of Orion is fully fifteen 

 degrees from the visible margin of the Milky "Way ; but it 

 may perhaps belong to the prolongation of that branch of 

 the galaxy which runs from a and e Persei, and appears to 

 lose itself near Aldebaran and the Hyades, and of which we 

 have already spoken (Yol. in. p. 128). The finest stars in 

 the constellation of Orion, which gave to it its ancient 

 celebrity, are considered as belonging to the zone of very 

 large, and probably comparatively near, celestial bodies, the 

 prolongation of which forms a great circle passing through 

 e Orionis and a Crucis into the southern portion of the 

 Milky Way ( 415 ). 



An earlier and very prevalent opinion ( 416 ), as to the 

 existence of a galaxy of nebulae intersecting the galaxy of 

 stars nearly at right angles, does not by any means appear 

 to be confirmed by later and more exact observations on the 

 distribution of the nebulae of regular form over the vault of 

 heaven ( 417 ) . There are, indeed, as has been already remarked, 

 large assemblages of nebulae near the northern galactic 

 and a considerable number near the Southern Eish 

 but from the many interruptions which occur we cannot 

 say that we have found a zone of nebulae passing through 

 these two poles and forming a great circle of the sphere. 

 William Herschel in 1784, at the conclusion of his first 

 treatise on the structure of the heavens, had indeed deve- 

 loped such a view, but doubtfully, and with the caution 

 which became so eminent an investigator of nature. 



Of the irregular, or rather unsymmetrical nebulae, some, (as 

 those in the sword of Orion, near 17 Argus, and in Sagitta- 



VOL. in. a 



