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THE 



AMERICAN JOURNAL OF SCIENCE 



[THIRD SERIES.] 



Aet. XLIY. — Further Study of the Solar Corona ; by 

 Frank H. Bigelow.* 



It was one of the proposed objects of the U. S. Eclipse 

 Expedition to West Africa, in December, 1889, to make an 

 effort to secure some photographs of the Solar Corona on a 

 large scale, in order that certain measurements might be taken 

 which would test fully the validity of the equation that I have 

 assigned to the coronal curves. Inasmuch as we failed to 

 obtain the desired pictures, in consequence of the clouds that 

 prevailed during the minutes of totality, I have since my 

 return to the United States made a series of measures upon 

 photographs of the Coronas of 1878, July 29, 1 889, Jan. 1, and 

 1889, Dec. 22, which have been generously placed at my dis- 

 posal by the Superintendent of the Naval Observatory, and by 

 the Directors of the Harvard College and the Lick Observato- 

 ries respectively. I am also greatly indebted to Professor 

 William Harkness for allowing me to use the Transit of Yenus 

 Measuring Engine, by Stackpole, and for all needful assistance. 

 Six pictures have been measured, two La Junta negatives of 

 July 26, 1878, taken by Professor Hall, two Creston negatives 

 of July 26, 1878, by Professor Harkness, one positive of Jan. 

 1, 1889, by Professor W. H. Pickering at Willows, Cal., and 

 one negative by Mr. Burnham at Cayenne, S. America, Dec. 

 22, 1889. As the computations are quite heavy the results of 

 only one are presented with this paper. 



* Read before the American Association at Indianapolis, August 22d, 1890. 



Am. Jour. Sci. — Third Series, Vol. XL, No. 239.— Nov., 1890. 

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