A. MATHEMATICS AND ASTRONOMY. 5 



so far as we know, the first and only one to recognize it dur- 

 ing an eclipse by its own bright lines. 



The well-organized parties under the eminent English spec- 

 troscopists Messrs. Roscoe and Lockyer were prevented by 

 clouds from seeing any thing ; and, so far as we can learn, 

 none of the other observers did more than confirm some of 

 the phenomena observed by Winlock and his party. 



All the observers describe the continuous spectrum of the 

 corona as beino; devoid of all dark lines. This has been re- 

 garded as showing that the corona shone almost entirely by 

 its own light, because the dark lines are seen in the spectra 

 of all bodies which shine by reflected sunlight. But the po- 

 lariscope observations seem to show that there is much re- 

 flected sunlight in the corona. In Professor Winlock's party, 

 Professor Langley observed with a Bavart's polariscope at- 

 tached to a small telescope. The bands were distinctly seen 

 on the corona, and were brightest where normal or tangen- 

 tial to the limb. It is understood that Professor Pickering, 

 who used an Arago's polariscope, also saw evidences of po- 

 larization. But Professor W. G. Adams, of London, who ob- 

 served in Sicily, saw no evidence of polarized light, while his 

 assistants saw it very plainly. On the whole, the evidence 

 seems strongly in favor of polarization, and therefore of some 

 reflected light. 



Striking a general average among all the observations and 

 the conclusions to be deduced from them, it may be fairly con- 

 cluded that the sun is surrounded by four or more envelopes. 



1. A gaseous layer about five hundred miles thick, contain- 

 ing a great number of chemical elements, which produce the 

 ordinary dark lines of the spectrum by elective absorption. 

 2. The red chromosphere and prominences, composed mainly 

 of glowing hydrogen, and extremely irregular in outline. 3. 

 A sphere of some very rare gas, hitherto unknown, shining 

 mainly by its own light, and forming the base of the corona : 

 the new green line proceeds from this- gas. 4. Irregular 

 masses of light, extending a degree or more from the limb of 

 the sun, the origin and nature of which are involved in obscu- 

 rity. These are found in the photographs, so they can not 

 be purely optical illusions ; but it is still an open question 

 whether they originate in our atmosphere, in the planetary 

 spaces, or in the neighborhood of the sun. 



