STELLAR DISTRIBUTION. 215 



took a series of investigations which resulted in 

 his famous theory of the Universe. This was 

 published in his work 'Etudes d'Astronomie 

 Stellaire,' which was published in 1847. His 

 researches were based on the star-catalogues of 

 Bessel, Piazzi, and others ; and dealing with 

 52,199 stars, he discussed the number of stars 

 in each zone of Right Ascension. He found, 

 in the words of Mr Gore, " that the numbers 

 increase from hour i to hour vi, where they 

 attain a maximum. They then diminish to a 

 minimum at hour xiii, and rise to another but 

 smaller maximum at hour xviii, again decreas- 

 ing to a second minimum at hour xxii. As the 

 hours vi and xviii are those crossed by the 

 Milky Way, the result is very significant." 

 He concluded the Galaxy to be produced by a 

 collection of irregularly-condensed clusters, the 

 stars condensed in parallel planes. Next, he 

 considered the Universe as perhaps infinitely 

 extended in the direction of the Galaxy, and 

 accordingly he put forward the idea that the 

 light from the fainter and more distant stars 

 was extinguished in its passage through the 

 ether of space, which he regarded as imper- 

 fectly transparent. The theory, as Struve pro- 

 pounded it, was disposed of by Sir John Herschel, 

 who remarked that we were not permitted to 



