69 



the least trace of the solar "1474 matter" it has ever 

 exhibited since the spectroscope discovered its presence, 

 is a proof that it, too, follows the periodicity characteris- 

 tic of the sun. In a few years the sun spots wall again 

 become numerous, for their period is known ; if the 

 corona should then, as is confidently expected, exhibit 

 the characteristics so marked in 1869 and 1870, when the 

 sun was in great activity, the proof wall be still more 

 complete. 



It is remarkable that while the 1878 corona contained 

 less of the solar matter than formerly, it was more ex- 

 tended and exhibited more plainly the evidences of re- 

 flected light. The advocates of the view that it is mainly 

 caused by reflection from meteoric substances in the vicin- 

 ity of the sun find in this circumstance an argument for 

 their theory ; and some who before have believed that the 

 inner corona was solar and the outer atmospheric in ori- 

 gin have changed to the meteoric theory. The sketch 

 made by Prof. Abbe on the slope of Pike's Peak shows 

 in a very striking way the extent of the corona as seen 

 in high altitudes without telescopic aid. The observer 

 has advanced the theory that the long bands of light are 

 the £:rand meteor streams which the earth meets in Augfust 

 and November, the tapering of the bands being due to 

 perspective. No other person, as far as known (for but 

 few of the reports of the last eclipse have yet been pub- 

 lished) has been so definite in designating the position of 

 the meteoric bodies reflecting the coronal light, but the 

 belief that this is the explanation of at least that portion 

 of the corona farthest removed from the sun has been 

 strengthened by the recent observations. 



It has been customary for some observers to spend the 

 time of totality in the search for new^ planets near the 

 sun. To facilitate the work, a chart of stars is made 



ESSEX INST. BULLETIN. XI 6 



