1870.] The Solar Eclipse of August last. 29 



Commencing at noon in Alaska, the line of totality ran through 

 British America, passing through the south-west corner of 

 Minnesota diagonally through Iowa, crossing the Mississippi 

 near Burlington, thence through Illinois, West Virginia, and 

 North Carolina, and entering the Atlantic Ocean on the North 

 Carolina coast, near Beaufort. The path of the eclipse through 

 the more inhabited parts of the continent literally bristled with 

 telescopes ; the whole line being converted into one vast observatory. 

 Although the duration of totality was less than in India last year, 

 the circumstances were more favourable for observation, the heat 

 being less and the position of the sun more convenient for observa- 

 tion, instead of being almost vertical. The principal points which 

 had to be observed were the nature of the protuberances, examined 

 with the spectroscope and recorded photographically ; the nature 

 of the corona ; and the detection, if possible, of any intra-Mercurial 

 planet. As might be expected from the easy accessibility of the 

 entire line of totality, this eclipse has been most thoroughly observed 

 by numerous parties, the report of whose work will in due time be 

 presented to the scientific world. 



The most important observations were those recorded by the 

 Iowa expedition, towards the expenses of which 5000 dollars had 

 been voted by Congress. The writer has to thank his friend, Dr. 

 Henry Morton, Professor of Chemistry in the University of Penn- 

 sylvania, who had the superintendence of this expedition, for full 

 details of the results obtained, together with some exquisite photo- 

 graphs of the phenomena of totality, &c. These pictures show, in 

 the first place, very fine definition in the telescope employed, as the 

 roughness or mountainous character of the moon's edge is clearly 

 given in the pictures of partial phase, as well as the sun-spots and 

 surrounding faculae. 



The telescopes which were available for the purpose were two 

 fine Munich Equatorials, of 6 inches aperture, with clockwork, and 

 also an excellent Dolland, of 4 inches aperture, equatorially mounted, 

 but without clockwork. It was concluded that on account of the 

 risk of local clouds it would be desirable to take all these instru- 

 ments, and distribute them over some distance on or near the 

 central line, and it was also considered that at least five skilled 

 operators would be necessary to each instrument. The next 

 important point was the choice of the party, and it was soon 

 found that an excellent selection might be had from among those 

 whose position or engagements would allow them to volunteer 

 without other compensation than the moral one contingent on 

 success ; and after a few changes, rendered necessary by sickness 

 or other inevitable cause, the party as finally constituted consisted, 

 besides Professor Morton, of Professor A. M. Mayer, Ph.D. ; 

 Professor C. F. Himes, Ph.D.; Messrs. J. Zentmayer, 0. H. Willard, 



