1847] Association of Geologists and JVaturalisis. 203 



light. The number of stars was too great to attempt counting 

 them; many were, however, readily located and mapped. The 

 double character of the brightest star in the Trapezium was read- 

 ily recognized with a power of 600. This is " Struve's 6th star;" 

 and certain of the stars composing the nebula were seen as dou- 

 ble stars under the power. It should be borne in mind that this 

 nebula, and that of Andromeda, have been the last stronghold of 

 the nebular theory; that is, of the idea first thrown out by the 

 elder Herschel, of masses of nebulous matter in process of con- 

 densation into systems. The nebula in Orion yielded not to the 

 unrivaled skill of both the Herschel's armed with their excellent 

 reflectors. It even defied the power of Lord Rosse's three foot 

 mirrors, giving " not the slightest trace of resolvability" or 

 separation into a number of single sparkling points. And 

 even when, for the first time, Lord Rosse's grand reflector, of 

 6 foot speculum, was directed to this object " not the veriest trace 

 of a star was to be seen." Subsequently his lordship communi- 

 cated the result of his farther examination of Orion, as follows: 



" I think I may safely say that there can be little, if any doubt 

 as to the resolvability of the nebula. We could plainly see that 

 all about the Trapezium is a mass of stars, the rest of the nebula 

 also abounding in stars, and exhibiting the characteristics of re- 

 solvability strongly marked." 



This has hitherto been considered as the greatest effort of the 

 largest reflecting telescope in the world, and this our own tele- 

 scope had accomplished. I feel deeply sensible of the odiousness 

 of comparisons, but innumerable applications have been made to 

 me for evidence of the excellence of the instrument, and I can see 

 no other way in which the public can be made acquainted with 

 its merits. 



With sincere respect and esteem, 



I remain, sir, your obedient servant, 



W. C. BOND. 



On the JVebular Hypothesis, by Prof. B. Peirce. 



This vast and magnificent speculation rested on the tripod of 

 geology, physical astronomy and celestial mechanics. The argu- 

 ment from geology will not be considered here. The argument 

 from physical astronomy has been much shaken by the resolution 

 of many of the great nebula}. There are two kinds of nebulai: 

 the irregular, which are resolvable into stars; the rounded, well 

 defined nebulae have been the strong holds of the partizans of the 

 nebular theory; they resemble comets. The nebula in Androme- 

 da, hitherto unresolvable, has been seen at Cambridge to be of an 

 irregular outline, and is, therefore, probably resolvable. Since 



