112 On 7] Argils and Nebula^ 



northern outline of this loop is moving north, proceeding so 

 as to approximate this outline more to its appearance in 

 1838 than any previous drawings show it. Yet this outline 

 is so faint that owing to the brightness of the included 

 nebula the eye traces it with difficulty and at first takes the 

 boundary of the included nebula as that of the lemniscate 

 which viewed thus would appear to be much more narrowed 

 than it has really been. 



The 8 margin of the gulf has retired still further from 634 

 and 616 H., and left 634 in mid-channel (a close double star 

 as the Great Telescope now shows it), and 616 well clear of 

 the nebula. The fading away of nebula is still extending 

 around 77 as a centre, although that star is still apparently 

 nebulous, and a very faint nebulous bridge only joined to the 

 nebula, north preceding. The oval patch seems to be 

 changing its form and closing up, and the head star of the 

 minute "Orion" is now never seen, and the Np star of 

 the pentagon rarely so. This configuration of stars has on 

 several occasions given the vivid impression of being "set" 

 on the nebula, with the exception of the two just mentioned, 

 and I incline to think that the latter are on the other side 

 of the nebula, the former on the side next the earth. 



It may be interesting to add that on many occasions, and 

 these always of the best definition, the nebula gave a dis- 

 tinct stereoscopic impression to my eye, particularly when 

 under high powers. The margin of the lemniscate always 

 appearing the thickest part, and the vacuity appearing like 

 a huge snowy cave with uneven woolly sides. 



With the kind assistance of Mr. Martin, an amateur in 

 astronomy, I have commenced a catalogue of the stars 

 observed, 109 of which have been observed within the-^th 

 of a square degree immediately surrounding -q. Within this 

 space Herschel's 18 inch aperture recorded only 39. 



Since reading the above paper at the Royal Society of 

 Victoria, I have had four opportunities of re-examination of 

 this nebula, now rising into position in the evenings, and its 

 appearance is in the main that represented by my last 

 drawing and description, no important change having since 

 occurred. The lemniscate has apparently gone through a 

 cycle of changes, and has now become once more stationary. 



Learning from Mr. Russell that he intends to revise his 

 paper, published in 1871, I may defer remark upon it until 

 then, except to corroborate Mr. Russell's remarks as to the 

 alleged colours of stars near tj observed by Mr. Abbott. I 



