W. A. Norton— Physical ConstUuhon of the Sun. oH 



until 1^ Se-n when it reappeared, but with a change of reLati\ 

 position ; it was then between the brown spota The shado 

 of the second satellite, very black at first dimmed as it came 1 

 the center, and became elongated. 



Jan. 13, 1871.— Two white spots seen near the northern ed^i 

 seemed to change in relative position in the course of hall :i 



Jan. 16, 1871.— The passages of the first satellite and ol' tl 

 shadow were carefully watched. The satellite was seen thn n:- 

 nearly the whole transit; it was lost for about 20 minutes w iu 

 neiir'the center — at this time the shadow became idon.iiatn 



A hirge white spot was seen above the most northern dark 

 belt. 



Jan. 19, 1871.— Three large white spots were seen on the 

 dark equatorial belt. The third satellite was on the planet and 

 was smaller than any one of these spots. 



In watching the changes of Jupiter's bright cloudy beU> • 

 of its dark bands, one is continually reminded of the chan- 

 in the sun's photosphera Although the variations are < 

 marked on Jupiter than on the sun, yet it is true of both tli ■ 

 drawings made at intervals of half an hour would show ditler- 

 ent relations of dark and light spots. 



The changes in the satellites seem to me peculiar. I have 

 watched the first satellite a good deal, and while I have never 

 seen it enter upon, or leave the disc as other than a white circu- 

 lar object, either I have lost it at the center, or it has changed 

 in shape and color,— becoming elongated toward the polar re- 

 gions, and assuming a reddish-brown hua The impression 

 made upon the observer is that of the interposition ol some 

 medium through which it is seen dim and distorted. 



: byPro- 



^ Among the recent theories of the Physical Constitution of 

 the Sun, based on the later discoveries, astronomical and spec- 

 troscopic, that propounded a few years since by f^-f^y^^^^ 

 been most favorably received. It is an essential feature ot tuis 

 tbeory that the sun4 mass consists wholly, or in a great degree 

 of gases or vapors ; and that a process of interchange ot solar 

 matter betweeS the interior and the photosphere is m incessant 

 operation, in ascending and descending currents, by which tne 

 ♦Comptes Rendus, vol. Ix, pp- 89 and 138. 



