THE BOUNDARIES OF ASTRONOMY. 239 



Come, a fraternal grasp, thou hand of stone ! 

 The flesh that once was thine is now mine own. 



v. 



Sublime is life, though in beginnings base 

 At first enkindled. In this clod of mold 

 Beats with faint spirit-pulse the heart of gold 

 That warms the lily's cheek ; its silent grace 

 Dwells unborn 'neath this sod. Fain would I trace 

 The potent mystery which, like Midas' hand, 

 Thrills the mean clay into refulgence grand ; 

 For, gazing down the misty aisles of space 

 And time, upon my sight vast visions throng 

 Of the imperial destiny of man. 

 The life that throbbed in plant and beast ere long 

 Will break still wider orbits in its van 

 A race of peace-robed conquerors and kings, 

 Achieving evermore diviner things. 



From " Idyls of Norway.'''' 



* 



THE BOUNDAKIES OF ASTRONOMY. 



11. 



THE NEBULAR HYPOTHESIS. 

 Br KOBERT S. BALL, F.E. S., 



ASTRONOMER-BO TAL OF IRELAND. 



THE whole range of astronomy presents no speculations which have 

 attracted more attention than the celebrated nebular hypotheses 

 of Herschel and of Laplace. We shall first enunciate these specula- 

 tions, and then we shall attempt to indicate how far they seem to be 

 warranted by the actual state of scientific knowledge. In one of his 

 most memorable papers, Sir William Herschel presents us with a sum- 

 mary of his observations on the nebulae, arranged in such a manner as 

 to suggest his theory of the gradual transmutation of nebulae into stars. 

 He first shows us that there are regions in the heavens where a faint 

 diffused nebulosity is all that can be detected by the telescope. There 

 are other nebulse in which a nucleus can be just discerned ; others 

 again in which the nucleus is easily seen ; and still others where the 

 nucleus is a brilliant, star-like point. The transition from an object 

 of this kind to a nebulous star is very natural, while the nebulous stars 

 pass into the ordinary stars by a few graduated stages. It is thus 

 possible to enumerate a series of objects, beginning at one end with 

 the most diffused nebulosity, and ending at the other with an ordinary 



