Ixxxviii NOTES. 



( 9 ) p. 240. Kosmos, Bd. ii. S. 369 (Eng. ed.p.328). 



(^) p. 241. "Ex his autem tres illse pene inter se contignee Stellas, 

 cumque his aliee quatuor, velut trans nebulam lucebant : ita ut spatium circa 

 psas, qua forma hie conspicitur, multo illustrius appareret reliquo omni 

 cselo ; quod cum apprime serenum esset ac cerneretur nigerrimum, velut hiatu 

 quodam interruptum videbatur, per quem in plagam magis lucidam esset pros- 

 pectus. Idem vero in hanc usque diem nihil immutata facie seepius atque 

 eodem loco conspexi ; adeo ut perpetuam iilic sedem habere credibile sit hoc 

 quidquid est portenti : cui certe simile aliud nusquam apud reliquas fixsas 

 potui animadvertere. Nam cseteree nebulcsse olini existirnataj, atque ipsa via 

 lactea, perspicillo inspects, nullas nebulas habere comperiuutur, neque aliud 

 esse quam plurium stellarum congeries et frequentia" (Christiani Hugenii 

 Opera varia, Lugd. Bat. 1724, p. 540-541). The magnifying power employed 

 by Huygens in his 23 -foot refractor was estimated by himself at only one 

 hundred times (p. 538). Are the " quatuor stellse trans nebulam lucentes" 

 the stars of the trapezium ? The small and very rough drawing (Tab xlvii. 

 fig. 4, phenomenon in Orione novum) represents only a group of three stars ; 

 and indeed near an indentation which might be taken for the Sinus magnus. 

 Perhaps only the three stars of the trapezium which are between the 4th and 

 7th magnitudes are indicated. Dominique Cassini boasted that he was the 

 first person who had seen the fourth star. 



( m ) p. 241. William Cranch Bond, in the Transactions of the American 

 Academy of Arts and Sciences, new series, Vol. iii. p. 87-96. 



( 422 ) p. 242. Cape Observations, 54-69, PI. viii. ; Outlines, 837 and 

 885, PI. iv. fig. 1. 



C 123 ) p. 242. Sir John Herschel, in the Memoirs of the Astron. Soc. Vol. 

 ii. 1824, p. 487-495, PI. vii. and viii. This latter drawing gives the nomen- 

 clature of the different regions of the nebula in Orion which has been exa- 

 mined by so many astronomers. 



() p. 242. Delambre, Hist, de 1'Astr. moderne, T. ii. p. 700. Cassini 

 reckoned the appearance of this fourth star (" aggiunta della quarta stella alle 

 tre coutigue") among the alterations which he considered the nebula in Orion 

 had undergone in his time. 



( 42S ) p. 242. " It is remarkable that within the area of the trapezium no 

 nebula exists. The brighter portion of the nebula immediately adjacent to 

 the trapezium, forming the square front of the head, is shown with the 

 18 -inch reflector broken up into masses, whose mottled and curdling light 

 evidently indicates, by a sort of granular texture, its consisting of stars ; and 



