312 ANNUAL OF SCIENTIFIC DISCOVERY. 



the lit'io;lit of the lar2;e protuberance measured, and found to be 

 '2' -15", or more than 7(),0U0 miles, loO.OOO at the base. 



While still guziiiir, a ray of light suddenly Hashed out, and the 

 total i'clipse ot Aug. 7th was over. 



The duration of totality, according to the chronograpli records, 

 was 2 minutes and 42 seconds. Tlie hirge protuberance, how- 

 ever, remained visible for 5 minutes and o seconds after tlie sun 

 had apjx^ircd, or, as Mr. Swift reports, until it was apparently 

 lifted up by the advancing crescent of solar light. 



Previous to the beginning of the eclipse, we set up a number 

 of light wooden rods, indicating the direction of stars and planets. 

 Prof. Twining and Mv. Marshall succeeded in seeing tSalm-n 8 

 minutes belore, and Venus 4 minutes before, totality. During 

 thi^ totality'. Mercury, Venus, Mars, Saturn, and a number of 

 bright stars, were visible to the naked eye. 



Observations made by Prof. Smith, with a thermometer exposed 

 to the direct )a\ s of the sun, showed a variation of 42 degrees 

 during the })rogiess of the eclipse. 



The observations of Mr. House, with a thermometer placed in 

 the shade, showed a variation of 13 degrees. 



Prof. David iNlurray, at my request, prepared the paper on the 

 physical plienomena, which is herewith appended. 



'Phe peculiar phenomena which have attracted so much atten- 

 tion in solar eclipses are only visible during the brief period of 

 totality. This, in the present case, only extended through 2 

 minutes and 43 seconds. The ditFieultv of observin2: them lies in 

 this exceeding brevity, and in the fact that, no matter how much 

 the observer may have studied the experiences of others, the phe- 

 nomen| comes upon him as a complete surprise. The moment 

 the last ray of light disappears with the extinguishment of Bailly's 

 Beads, there bursts upon him a vision so marvellously l)eaulit'ul, 

 so startling by its novelty, that iiis self-possession and self-control 

 desert him, and leave him, for an instant, a helpless gazer. As 

 soon as he can collect his thoughts, and tries to marshal them into 

 order, he will lind especially two phenomena of notable interest. 



In immediate contact with the solar disc, it ai)pears as a clear, 

 silvery light, as bright as the brightest i)art of an aurora, and 

 scmiewhat resembling it in eonsistenc}'. Farther out, it appears 

 streaked with pencils radiating in the direction of the centre. 

 These rays are more esjjccially noticeable at 5 points of the circum- 

 ference, 2 of them pointing upwards and outwards, and 3 hav- 

 ing a general downward direction. These prongs could be traced 

 thiongh a distance even exceeding the diameter of the sun, and 

 near one of theuj w^as visible a curved mass of light, in shape re- 

 sembling the petal of a flower. On the upper edge of the disc 

 was j)lainly seen an arch of light, parallel with the edge, and 

 within the boundary of the corona. 



It shoukl be stated that the pin nomenon of the corona is best 

 observed wiili the naked eve, and cannot be included w iihin the 

 field of any ordinary telescope. Our party are indebted to the 

 observations of Mr. Ho>twick, of !Maitoon, and Gen. Keifer, of 

 Springfield, Ohio, for the best configuration of the corona. 



