10 W. A. Norton on the Corona in Eclipses of the Sun. 



Results of Observations on the Corona made at the Total Eclipse 

 of August 1, 18G9. 



The observations made on the Corona on the occasion of the 

 echpse of 1869, have furnished several striking confirmations 

 of the theory that it is an auroral phenomenon. 



1. The observed form and structure of the Corona. — I will first 

 adduce the results of my own observations. These were made 

 at Des Moines, Iowa, with the naked eye, and a good opera- 

 glass, and were chiefly confined to the Corona. When the 

 totality commenced, and the beautiful corona stood revealed, 

 like a new creation, against the dark background of the sky, 

 almost the first striking feature that caught my attention 

 was ttie great inequality in the extent of ' its outstreaming 

 m dififerent directions, and its consequent in-egularity of out- 

 line. This outstreaming or luminous radiation, was particu- 

 larly conspicuous from the eastern limb, nearly in the direc- 

 tion of the plane of the ecliptic or the sun's equator. It could be 

 distinctly traced in that direction to a distance from the sun 

 equal to his own diameter. For an extent of some 15° on 

 -either side of the ecliptic, individual hair-like streamers, seem- 

 ingly nearly parallel to the ecliptic, extended out a large fraction 

 ot this distance. From the opposite limb, and in the opposite 

 direction the coronal streamers were conspicuous, but of less 

 extent than m the direction of the ecliptic toward the east, 

 l^rom the polar regions other pointed masses of light -extended 

 out to considerable distances, but not so far as those just 

 noticed. They seemed to be composed like the others, of rays 

 or hair-hke luminous radiations, more or less distinct. The 

 separate luminous lines appeared to Professor Eastman, from 

 the U. b. Naval Observatory, (who observed the corona at the 

 same station, through a small telescope) to converge more or 

 less. This convergence I failed to detect ; but I distinctly 

 noticed that the outstreaming mass from near the north pole oi 

 the sun had approximately the form of a triangle with curved 

 sides, convex outward, but the triangular outline appeared 

 as It resulting from the intersections of individual radiations, 

 ous m ""^ " *^^ <^^^n{ie boundary of a stationary lurain- 



The corona had a white silvery luster, and appeared at times 

 suttusedwith a delicate rosy tinge, but this wn^ ])robably a 

 subjective effect No flickering or variation ol' tii. lunter of 

 the corona, was observable during the totality Nor was there 

 any noticeable change in its general form, or in the extent of its 

 luminous radiations, though rcarefully watchcMl forsu-h chan-t's. 

 Dr B. A. Gould, who was stationed^at Burlin-^'.n invn, and 

 other observers, thought that both the luster and extmt of the 

 radiating masses, or "star points," underwent material varia- 



