PORTION Otf THE COSMOS. NEBULAE. 225 



all that had been observed in the part of the heavens visible 

 from middle Europe, and in the next immediately succeeding 

 five years (1834 to 1838), we find Sir John Herschelat the 

 Cape of Good Hope examining with a 20-foot reflector the 

 whole of the heavens visible from thence, and thereby adding 

 to the above 2307 nebulae and star clusters, a fresh list of 

 1708 positions ( 379 ) ! Of Dunlop's catalogue of southern 

 nebulae and clusters (629 in number, observed at Paramatta 

 from 1825 to 1827 with a 9-foot reflector ( 38 ) having a 

 mirror of 9 inches diameter), only one- third were transferred 

 to Sir John HerscheFs work. 



A third great epoch in the knowledge of these mysterious 

 celestial objects has been commenced by the construction of 

 the admirable 50-foot telescope ( 381 ) of the Earl of Eosse 

 at Parsonstown. All the questions which had been agitated 

 in the long course of fluctuating opinions, and in the dif- 

 ferent stages of development in cosmical contemplation, now 

 became afresh the subjects of animated discussion in the 

 controversy between the nebular hypothesis and the asserted 

 necessity of relinquishing that hypothesis altogether. From 

 the accounts which I have been able to collect on the 

 authority of distinguished astronomers long conversant with 

 the nebulae, it appears that out of a great number of objects 

 hitherto supposed to be uri resolvable, taken as it were by 

 chance from all classes of such objects in the catalogue of 

 1833, almost all (Dr. Robinson, the Director of the Obser- 

 vatory of Armagh, gives above 40), were completely resolved 

 ( 382 ). Sir John Herschel expresses himself in a similar 

 manner in his opening speech at the Meeting of the British 

 Association at Cambridge in 1845, as well as in the Outlines 

 of Astronomy in 1849. He says : " the reflector of Lord 



