446 LETTERS OF A CITIZEN. 



Des Fontaines spoke flatteringly of the botanical collections of 

 M. Lesson. It was, indeed, flattery to speak highly of the botan- 

 ical department of the Astrolabe, as we shall see anon. Arago 

 was charged by the academy with the examination of the physical 

 observations. He did not wish, he said, to confine himself to a 

 simple inventory. As in the voyages of Freyeinet and Duperrey, 

 he attempted to discover the results with which science would be 

 enriched. But here " disappointment followed disappointment." 

 Discouraged " by the poverty of scientific observations recorded 

 in the official registers," he examined the nautical journals. Here, 

 again, he was disappointed ; while those of the former navigators 

 had been so varied, so rich, so interesting. The farther he ad- 

 vanced in his investigations, the more forcibly was he impressed 

 with the idea that the commander of the Astrolabe had voyaged 

 for three years " with his eyes and ears shut." " Had he" (D'Ur- 

 ville) " seen," Arago inquired, " the zodiacal light ? During the 

 fine nights of the tropics, had he ascertained its dimensions, its 

 limits, its exact position ? He had turned, one after another, all 

 the pages of the register of M. D'Urville, and was not able to 

 find one remote allusion to this remarkable phenomenon." Not 

 yet disheartened, the transparency of the ocean, the changes of 

 colour produced by the winds, according to their force and direc- 

 tion, the sudden variations of temperature, upon which Franklin 

 and Williams had already published the commencement of a work 

 so encouraging to the marine ; the Aurora Australis ; each of 

 these curious phenomena, the exact determination of which has 

 been sought with such ardour by the students of physical science, 

 was, Arago says, in succession the object of his laborious research ; 

 but in every case he arrived at the last page without having found 

 a word upon the subject. 



At the frequent solicitations of Captain D'Urville and M. Tas- 

 teau, the editor of the voyage, Arago was prevailed upon, as he 

 says, " by the desire of obliging more than anything else," to make 

 out a oigest. He had found here and there in the MSS. obser- 

 vations on the temperature of the sea, which, at that time, he sup- 

 posed were correct f but many of these experiments he subse- 

 quently found "were complete failures," though even these were 

 not without their use for future observers. It was especially 

 desirable to determine if submarine currents, directed from the 



