48 COSMOS. 



impression on the unaided eye as might be excited by two 

 bright portions of the Milky Way, equal in size and isolated 

 m position. The smaller cloud entirely disappears in clear 

 moonlight, while the larger one only loses a considerable por- 

 tion of its brightness. Sir John Herschel's delineation of 

 these objects is admirable, and accurately corresponds with 

 the vivid impressions excited in my own mind during my so- 

 journ in Peru. Astronomy is indebted to the laborious re- 

 searches of this observer at the Cape of Good Hope in 1837, 

 for the first accurate analysis of this most wondrous aggrega- 

 tion of heterogeneous elements.* He found a large number 

 of individual and scattered stars, stellar swarms and globular 

 clusters of stars, and both oval regular and irregular nebulas 

 more closely thronged together than in the nebulous zone of 

 Virgo and Coma Berenices. The nubecula can not, there- 

 fore, from this condition of complicated aggregation, be re- 

 garded, as has too often been done, either as exceedingly 

 large nebulae, or as detached portions of the Milky Way ; 

 for, with the exception of a small zone lying between the 

 constellation Ara and the tail of the Scorpion, globular stel- 

 lar clusters and oval nebulae are of rare occurrence in the 

 Galaxy. f 



The Magellanic Clouds are not connected with one anoth- 



* Cosmos, vol. i., p. 85, and note. See Observ. at the Cape, p. 143- 

 164; pi. vii. gives a representation of the Magellanic Clouds as they ap- 

 pear to the naked eye ; pi. x. the telescopic analysis of the Nubecula 

 Major, and pi. xi., fig. 4 ( 20-23), affords a special view of the nebula 

 Doradus. Outlines, 892-896, pi. v., fig. 1, and James Dunlop in the 

 Philos. Transact, for 1828, part i., p. 147-151. So erroneous were the 

 views of the earlier observers, that the Jesuit Foiitaney, who was great- 

 ly esteemed by Dominique Cassini, and to whom we are indebted for 

 many valuable astronomical observations in India and China, wrote as 

 follows so recently as 1685: ' Le grand et le petit nuages sont deux 

 choses singulieres. Us ne paraissent aucunement un amas d'etoiles 

 comme Praesepe Cancri, ni meme une lueur sombre, comme la nebu- 

 leuse d'Aiidromede, On n'y voit presque rien avec de tres grandes 

 lunettes, quoique sans ce secours on les voie fort blancs, particuliere- 

 ment le grand image." " The large and the small cloud are both very 

 remarkable objects. They do not appear a mere mass of stars, like 

 Prasepe in Cancer, nor are they a faint light, like the nebula in An- 

 dromeda. Very little is to be seen within these bodies even with large 

 instruments, although when observed without such optical aid they ap- 

 pear very white, and this is especially the case with the large cloud." 

 Lettre du Pere de Fontaney an Pere de la Chaize, Confesseur du Rot, 

 in the Lettres Edifiantes, Recueil vii., 1703, p. 78; and Hist, de V Acad. 

 det Sciences dep. 1686-1699 (torn, ii., Paris, 1733), p. 19. In my de- 

 scription of the Magellanic Clouds, in the text, I have exclusively fol- 

 lowed Sir John Herschel's work. 



t Cosmos, vol. iii., p. 145, and note. 



