92 THE COLOTJEED STAES ABOUT KAPPA CETTCIS. 



some otters ; and it is very remarkable that the changes in the 

 south preceding side are nearly all in E.A., while in those near 

 Beta, and in the following side, are in declination, as if the 

 cluster were made up of three sets of stars, two of which drift 

 from the third in different directions. 



It is a remarkable circumstance, which I cannot account for by 

 any peculiarity either in Sir John Herschel's or my own method, 

 that I have found, both in Eta Argus and this cluster, that it is 

 <the stars on the south preceding side which are drifting from the 

 others in the most remarkable manner. 



Five of Herschel's stars, all very small, I could not see ; but 

 this is not surprising, since he used a telescope 18^ inches in 

 diameter, and mine is only 7i inches ; but I was very much sur- 

 prised to find 25 which he did not see. Stars, which though all 

 small, are yet in most cases brighter than some of his which I 

 recognized, and if there when he examined the cluster, would 

 not have been omitted ; they are all well within the limits of his 

 map, and several in parts of it which must have been most care- 

 fully examined. Two of them are near Alpha, one near the 

 string of stars south following it, one between Beta and Delta, 

 and two in the triangle 50'- after Alpha, where Herschel shows 

 3 stars ; of the others, 5 precede Alpha from 18 to 25^- ; 5 follow 

 it from 15 to 25'-, and on the south side ; 8 are on the north 

 following side, and I on the south following. Their numbers in 

 my list are 2, 3, 4, 6, 7, 16, 19, 31, 60, 69, 73, 76, 79, 86, 110, 

 116, 117, 120, 123, 124, 125, 127, 128, 129, and 130. 



I may here mention that while preparing this paper it occurred 

 to me that it would be interesting to examine the object with the 

 old telescopes as far as possible, to see if any change in brilliancy 

 could be thus detected. I therefore first examined it with an 

 old telescope with a working aperture of i an inch, and 20 inches 

 focus — dimensions very near those of Lacaille's telescope. "With 

 this instrument, on a bad night, and the object six hours past 

 meridian, I saw distinctly four stars of the cluster, which are 

 separated much more than many which Lacaille took the trouble 

 to record separately ; yet he simply called this a nebula. With 

 the telescope of the old Parramatta mural circle, which is now 

 in the Observatory, and which has an aperture of nearly 2 inches, 

 and 25 inches focus, I could see fourteen stars, and glimpses of 

 many more which, if on the meridian, would be visible without 

 doubt. 



I may also mention that in my list there are twenty -four stars 

 above the 10th magnitude, and in Herschel's there are only seven, 

 thus compared : — 



Magnitude 6^ 7 7i 8 8| 9 9^ Total. 



Herschel 2 1 1 ... 8 ... 7 



Eussell ... 1 2 2 1 4 1 14 24 



