NOTES. Ixxxvii 



( 414 ) p. 238. The following may be cited as remarkable forms of irregular 

 uebulse : the one resembling the letter Omega (see Cape Observ. PI. ii. fig. 

 1, No. 2008, and which was also examined and described by Lamont and by 

 a highly promising too early deceased North American astronomer, Mr, 

 Mason, in the Memoirs of the American Philosophical Society, Vol. vii. p. 

 177) ; a nebula with six or eight nuclei (Cape Obs. p. 19, PL iii. fig. 4) ; a 

 comet-like tuft-shaped nebula in which the nebulous rays sometimes appear 

 as if proceeding from a star of the 9th magnitude (PI. vi. fig. 18, No. 2534 

 and 3688) ; a nebula resembling the shade profile of a bust (PI. iv. fig. 4, No. 

 3075) ; a creviced opening inclosing a thread-like nebula (No. 3501, PI. iv. 

 fig. 2). Outlines, 883 ; Cape Obs. 121. 



( 415 ) p. 239. Kosmos, Bd. iii. S. 185 (English edit. p. 127) ; Outlines, 

 785. 



( 416 ) p. 239. Kosmos, Bd. i. S. 157 and 415, Note 83 (Engl. edit. p. 141, 

 Note 113. Sir John Herschel, first edition of Treatise on Astronomy, 1833, 

 in Lardner's Cabinet Cyclopaedia, 616 ; Littrow, Theoretische Astronomic, 

 1834, Th. ii. 234. 



( 417 ) p. 239. See Edinburgh Review, Jan. 1848, p. 187 ; and Cape Obs. 

 96 and 107. " A zone of nebulas," says Sir John Herschel, " encircling 

 the heavens, has so many interruptions, and is so faintly marked out through 

 by far the greater part of the circumference, that its existence as such can be 

 hardly more than suspected." 



( 418 ) p. 240." There is, I think, no doubt," wrote Dr. Galle, " that the 

 drawing which you have sent me (Opere di Galilei, Padova, 1744, T.ii. p. 14, 

 No. 20) includes Orion's belt and sword, and therefore the star 6 ; but from the 

 obvious inaccuracy of the drawing, the three small stars in the sword, the middle 

 one of which is 6, and which to the unassisted eye appear to form a straight 

 line, are difficult to find. I should think that you have pointed out the star t 

 correctly, and that the bright star to the right of it, or the star immediately above, 

 is 0." Galileo says expressly : " In primo iutegram Orionis constellationem 

 pingere decreveram ; verum, ab iugenti stellarum copia, temporis vero inopia 

 obrutus, aggresbionem hanc in aliam occasionem distuli." The attention givem 

 by Galileo to the constellation of Orion is the more remarkable, because the 

 number of 400 stars which he thought he counted in about ten square de- 

 grees between the belt and the sword (Nelli, Vita di Galilei, Vol. i. p. 208) 

 misled Lambert (Cosmolog. Briefe, 1760, S. 155) so long afterwards into the 

 erroneous estimate of 1650000 stars in the whole firmament (Struve, Astr. 

 stellaire, p. i4, and Note 16). 



