THE STELLAR UNIVERSE. 



In fig. 60 is represented a drawing by Lord Rosse, made with 

 his large telescope, of a nebula situate in E A 5 h 27 m , N p D 96 2'. 

 This nebula surrounds the small star t Orionis, and has a diameter 

 equal to about a tenth part of that of the moon. 



Fig. 60. 



89. All the nebulae described above are objects generally of 

 regular form, and subtending small visual angles. There are 

 others, however, of a very different character, which cannot be 

 passed without some notice. These objects cover spaces on the 

 firmament, many nearly as extensive as, and some much more 

 extensive than, the moon's disk. Some of them have been re- 

 solved. Of those which are larger and more diffused, some 

 exhibit irregularly shaped patches of nebulous light, affecting 

 forms resembling those of clouds, in which tracts are seen in 

 every stage of resolution, from nebulosity irresolvable by the 

 largest and most powerful telescopes, to stars perfectly separated 

 like parts of the milky way, and ' ' clustering groups sufficiently 

 insulated and condensed to come under the designation of irregular 

 and, in some cases, pretty rich clusters. But, besides these, there 

 are also nebulae in abundance, both regular and irregular ; glo- 

 bular clusters, in every state of condensation, and objects of a 

 nebulous character quite peculiar, which have no analogy in any 

 other part of the heavens."* 



* Herschel, Outlines of Astronomy, p. 613. 

 44 



