20 COSMC.S. 



the nebt.lous bodies of the southern hemisphere, than of those 

 which were visible in Europe. Lacaille, moreover, success- 

 fully attempted to divide nebulae into classes according to their 

 apparent configuration ; he also was the first to undertake, 

 though with little result, the difficult task of analyzing the 

 heterogeneous contents of the Magellanic Clouds {nubecula 

 major et rmnor). If we subtract the 14 nebulae, which, even 

 with instruments of low powers, were perfectly resolved into 

 true clusters of stars, from the other 42 isolated nebulous spots 

 which Lacaille observed in the southern heavens, there re- 

 main only 28, while Sir John Herschel, by the aid of more 

 powerful instruments, as well as greater skill and superior 

 powers of observation, succeeded in discovering under the 

 same zone, and also independently of clusters, as many as 

 1500 nebulous spots. 



Devoid of personal knowledge or experience of the subject, 

 and originally ignorant of each other's attempts, although 

 both had very similar aims in view,* Lambert (from 1749) 

 and Kant (from 1755) speculated with admirable sagacity on 

 nebulous spots, detached galaxies, and sporadic nebulous and 

 stellar islands scattered singly through the realms of space. 

 Both inclined to the nebular hypothesis, and to the idea of a 

 perpetual development in the regions of space, and even of a 

 star-formation from cosmical vapor. The great traveler, Le 

 Gentil (1760—1769), long before his voyages, and his unsuc- 

 cessful observations of the transit of Venus, had imparted ani- 

 mation to the study of nebulae by his observations on the con- 

 stellations of Andromeda, Sagittarius, and Orion. He made 

 use of an object-glass 'of Campani's, 37 feet in focal length, 

 which was in the possession of the Paris Observatory. In 

 entire opposition to the views of Halley, Lacaille, Kant, and 

 Lambert; the intellectual John Michell declared (as Galileo 

 and Dominique Cassini had done) that all nebulae were stel- 

 lar clusters, aggregations of very minute or very remote tel- 

 escopic stars, whose existence would undoubtedly be some 

 day revealed by means of more perfect optical instruments.! 



* On the commnuity and difTerenco of ideas between Kant and 

 Lambert, as well as in reference to the period of their publications, 

 Bee Struve, Etudes d^Astr. Stellaire, p. 11, 13, 21, notes 7, 15, and 33. 

 Kant's Allgemeine Natur-Geschichte und Theorie des Himmels appear- 

 ed anonymously, and was dedicated to Frederick the Great, 175.5. 

 Lambert's Photometria, as already remarked, appeared in 1760; and 

 his Sammlung kosmologischer Briefe uher die Einrichtung des Welt- 

 baucM, in 17G1. 



t " Those nebulae," says John Michell in 17G7 (Pkilos Transact., vol 



