1868.] Mr. W. Lassell on the Great Nebula in Orion, 323 



great extent, it is possible, and indeed probable, that there may be some 

 spots on which the concentrated attention of any single observer has not 

 been given under the most favourable circumstances. In my own observa- 

 tions, the question of resolvability appeared always an interesting one to 

 settle, and therefore I gave quite as much attention to the detection of 

 stars as to the tracing of the nebula. 



The present drawing embracing much more of the extent of this nebula 

 than mine (if not, indeed, the whole of it), I am able to compare mine with 

 it only in part ; but, so far as my limits extend, the representations are 

 generally very coincident. In some parts there is a greater hardness than 

 I have seen ; but it is scarcely possible to convey a true impression of the 

 form of the convolutions of the nebula without intensifying them in some 

 degree. I recognized in my own observations more of the spiral or scroll- 

 like character of the nebula about the stars 51 and 57, first pointed out, I 

 believe, by Mr. Bond, than t find in this drawing. In an engraving sent 

 to me by Mr. Bond in 1863, in which photography had, as I understood, 

 been employed, this scroll-like appearance is strongly marked. 



On the question of a real change of form of the nebula, no positive con- 

 clusion can, I think, as yet be arrived at ; but as we have probably now 

 reached much more nearly to the practical limit of optical power in our 

 telescopes, future observations may be expected to be much more com- 

 parable with existing drawings than these are with those formerly made. 



The evidence of resolvability seems to me to be rather on the negative 

 side — my own deductions from what I have seen have been always in that 

 direction ; and such of the present observations as apparently look the other 

 way are, I consider, too vague and wanting in precision and certainty, to 

 establish it positively. 



[Received April 17, 1868.] 



In the account of my observations in Malta with the four-foot equa- 

 torial, published in the 36th volume of the Memoirs of the Koyal Astro- 

 nomical Society, there is but a slight reference to the Great Nebula of 

 Orion ; the immediate reason for which was, that the drawing I had made 

 was on too large a scale for appearing therein as an engraving, and I was 

 unwilling to subject it to a reduction of size. 



Moreover, as Lord Oxmantown's elaborate description and drawings of 

 this incomparable object have recently appeared in the Transactions of the 

 Ptoyal Society, and as the subject may be presumed to be a very interesting- 

 one, I beg leave to request of the Society their acceptance of my original 

 drawing (forwarded this day), which contains the sum of all I have been 

 able to make out (both of the details of the nebula and of the stars therein) 

 with the above telescope during my three-years' residence in the Island of 

 Malta. 



I also subjoin from my Journal the following few notes relative to some 



