852 Clusters, Nebidce, and Occultations. 



3jj indies, wliile with 144 it was not distinguishable : with 

 my present finder of 1^ inch aperture it is easily seen as a 

 large faint cloud ; it is a beautiful object, much resembling 

 Smyth's description, with 5f inches and a comet eye-piece, 

 power 29 ; with 64 the brighter part seems resolvable ; but it 

 will not bear 164. The reason of this peculiarity is simply its 

 great extent, which catches the eye as a whole in the large field 

 of a low power, even with a very small aperture, while, filling 

 the whole field of higher powers with feeble nebulous light, it 

 fails in that contrast with the dark sky which is required to 

 make it fairly visible. 



We will now turn to another contrast as great as can be 

 well imagined. » 



5. 34 M. (248 H.) Persei. This will be found in the fol- 

 lowing manner. Reverting to a Persei (Intellectual Observer, 

 vol. ii., 374) we must draw a line s, a little jp, which will soon 

 pass through a conspicuous star, usually little inferior to a ; this 

 is the well-known variable, one of the leaders of that wonder- 

 ful class, /3 Persei, or Algol, which also stands where two lines 

 from a Persei and 7 Andromedce meet at a right angle. Between 

 Algol and 7 Andromedce, but nearer to the former, and a little 

 n of the line joining them, the eye will catch a dim speck, a small 

 nebula properly so called, which the finder will resolve into stars, 

 and the telescope will spread out into a beautiful brilliant scat- 

 tered group, requiring a low power to show it well, but then 

 forming a truly magnificent field, including, as Smyth observes, 

 several coarse pairs. H. sees here about twenty stars, from 9 

 to 11 mag., and as many more of a smaller size. Its discoverer 

 was Messier, in 1764. 



OCCULTATIONS. 



These will be rather numerous during the present month, 

 including one which may prove well worth attention. Dec. 

 19th, ir Piscium, 6 mag., will disappear at 4h. 29m., and re- 

 appear at 5h. 13m. 23rd, I Tauri, 5| mag., will be hidden from 

 4h. 5m. till 4h. 52m. 24th, % 4 Orionis, 5 mag., from 5h. 38m. 

 for an hour : — unfortunately, near the time of full moon. 26th, 

 1 Cancri, 6 mag., will disappear at 12h. 38m., and reappear at 

 13h. 57m. 27th, A 1 Cancri, 6 mag., will be occulted from llh. 

 35m. till 12h. 54m. 28th, eo Leonis, 6 mag., from lOh. 59m. 

 till 12h. 13m. This being a very close double star, probably not 

 more than 0"*75 apart (I do not know its present measurement) 

 its occultation would provo of great interest, supposing that 

 the position of (lie limb is not coincident with that of the stars, 

 as, even with instruments that cannot divide the pair, their 

 duplicity would be made evident by a break in the loss or 

 rocovery of light. In this instance, the disappearance unfortu- 



