NEBULA. 313 



ecliptic, extending only from the southern wing of Virgo to the 

 extremity of Hydra and to the head of the Centaur, without 

 reaching its feet or the Southern Cross. A less dense accu- 

 mulation of nebulae in the northern hemisphere, which ex- 

 tends further south than the former, has been named by Sir 

 John Herschel the nebulous region of Pisces. It forms a zone, 

 beginning with Andromeda, which it almost entirely incloses, 

 stretching beyond the breast and wings of Pegasus, and the 

 band uniting the Fishes, and extending towards the southern 

 galactic pole and Fomalhaut. A striking contrast to these 

 accumulations presents itself in the barren region lying near 

 Perseus, Aries, Taurus, the head and chest of Orion, around 

 Auriga, Hercules, Aquila, and the whole constellation of 

 Lyra. tt If we divide all the nebulae and clusters of stars 

 contained in the Northern Catalogue (of Slough), and clas- 

 sified according to Right Ascension (as given in Sir John 

 Herschel's Observations at the Cape,) into six groups of four 

 hours each, we obtain the following result : 



B.Asc. Oh. .. 4h 311 



4 .. 8 179 



8 ..12 606 



12 ..16 850 



16 .. 20 121 



20 .. 239. 



By a more careful separation, according to Northern and 

 Southern Declination, we find that in the six hours Right 

 Ascension from 9h. 15h. there are accumulated 1,111 nebulae 



48 In reference to this barren region, see Observations at 

 the Cape, 101, p. 135. 



