10 



and even with eighteen inches is not likely to be over- 

 looked. 



Comparatively little attention was paid to nebulas and 

 clusters, from the moonlight, and the superior importance of 

 ascertaining the telescope's defining power. Of the few 

 examined were 13 Messier, in which the central mass of 

 stars was more distinctly separated, and the stars themselves 

 larger than had been anticipated ; the great nebula of Orion 

 and that of Andi'omeda shewed no appearance of resolution, 

 but the small nebula near the latter is clearly resolvable. 

 This is also the case with the ring nebula of Lyra ; indeed, 

 Dr. R. thought it was resolved at its minor axis ; the fainter 

 nebulous matter which fills it is irregularly distributed, 

 having several stripes or wisps in it, and there are four stars 

 near it, besides the one figured by Sir John Herschel, in his 

 catalogue of nebulae. It is also worthy of notice, that this 

 nebula, instead of that regular outline which he has there 

 given it, is fringed with appendages, branching out into the 

 surrounding space, like those of 13 Messier, and in parti- 

 cular, having prolongations brighter than the others in the 

 direction of the major axis, longer than the ring's breadth. 

 A still greater difference is found in 1 Messier, described by 

 Sir John Herschel, as " a barely resolvable cluster," and 

 drawn, fig. 81, with a fair elliptic boundary. This telescope, 

 however, shews the stars, as in his figure 89, and some more 

 plainly, while the general outline, besides being irregular 

 and fringed with appendages, has a deep bifurcation to the 

 south. 



From these and some other discrepancies. Dr. R. thinks 

 it of great importance that the globular nebulse and clusters 

 should be all carefully reviewed, as it is chiefly from their 

 supposed regularity that the hypothesis of the condensation 

 of nebulous matter into suns and planets has arisen, an 

 hypothesis which he thinks has, in some instances, been car- 

 ried to an unwarrantable extent. 



