1870.] The Solar Eclipse of August last. 39 



Mr. J. N. Lockyer in ' Nature,' for November 4th, he throws some 

 doubt on this conclusion, and hesitates to [regard the question as 

 S2ttled, were the new hypothesis less startling than it is. 



The most complete series of spectroscopic observations were 

 those taken of the prominences. During totality nine bright lines 

 w r ere observed by Professor Young in the spectrum of one of the 

 protuberances, viz. c dazzling in brilliancy; 1017*5 (near d, the 

 n a rubers refer to Kirchhoff's scale) very bright, but not equal to c ; 

 1250 + 20, very faint, position only estimated; 1350 ± 20, like 

 preceding ; 1474 (a little below e), conspicuous, but not more than 

 half as bright as 1017*5 ; f next to c in brightness ; 2602 ± 2, a 

 little fainter than 1474, position determined by micrometrical refer- 

 ence to the next; 2796, a little below G-; the well-known h y line 

 in brightness between 1017*5 and 1474; and finally h, or h 8, 

 somewhat brighter than 1474. b it is supposed was not seen ; on 

 account of a mistake in carrying that portion of the spectrum 

 through the field, there was no prominence on the slit. The lines 

 marked h in the coloured illustration are hydrogen lines. 



The opportunity which was afforded by the total obscuration 

 of the sun's light was taken advantage of to search for planetary 

 bodies between Mercury and the sun, but without success, although 

 Mercury, Venus, Mars, Saturn, Eegulus, and Arcturus were plainly 

 visible. The horizon all around was lighted up by a sort of dim 

 twilight for four or five degrees in breadth, and above this rim of 

 light hung a leaden canopy, increasing in depth towards the zenith. 



At the Ottumwa station a curious appearance was noticed by 

 Mr. Zentmayer. During the time that the pictures of the partial 

 phase were being taken at long intervals, the ground-glass plate 

 was put in the camera to note any irregularities in the clock move- 

 ment, should they occur. About twenty-five minutes before the 

 totality, Mr. Zentmayer observed some bright objects on the ground- 

 glass, crossing from one cusp to the other of the solar crescent. 

 Each object occupied about two seconds in passing, and they all 

 moved in right lines, nearly parallel, and in the same direction. 

 These points were well defined, and conveyed to the mind of Mr. 

 Zentmayer, who is accustomed to the use of the camera for photo- 

 graphic purposes, the strong impression of being images of objects, 

 and not points of light merely. It is, moreover, certain that the 

 objects, whatever they might be, must (in order to have produced 

 such sharply-defined images on the ground-glass) have been several 

 miles distant from the telescope, as even a point of light at a less 

 distance would have produced an enlarged image, with a hazy 

 border. 



The most complete account of the photographic operations is 

 recorded in the report to Professor Morton by Dr. Mayer, who was 

 the chief of the Burlington party. They arrived at their destination 



