L. Respighi on Vie Solar Protuberances. 287 



In regard to the spots, spectroscopic observations appear to 

 show that they are neither cavities nor clouds, but are merely 

 superficial modifications,* that is, partial obscurations of the 

 photosphere, produced probably, by scoria or scum floating 

 upon it. On the contrary, regard being had to the well defined 

 forms of the jets neighboring the spots, to their extraordinary 

 subtilty, and to their enormous energy, the supposition does not 

 appear to the author irrational, that the nuclei of the spots con- 

 sist of portions slightly projecting from the photosphere, of solid 

 masses or islands floating upon the liquid stratum which en- 

 velops the body of the sun. The immense chains of jets or 

 protuberances, w^hich rise ordinarily in the region of the spots, 

 might be the cause of those great transformations which are ob- 

 sen-ed in the latter, and determine, by their resistance in the 

 superficial strata, currents in a direction opposite to that of the 

 solar rotation, from which would result the proper motion of the 

 spots themselves. The limits of an article forbid entering into 

 the arguments by which Prof Eespighi endeavoi-s to justify these 

 conclusions, hypotheses, in great part at least, already advanced 

 bj others, but without that impress of plausibility and proba- 

 bility which they gain from the results of the spectroscopic ob- 

 servations discussed in this note. 



The note is accompanied by fourplatea Three of these rep- 

 resent 1-iO profiles of the sun, and the fourth contains sketches 

 of some of the more remarkable protuberances obsei-ved by the 

 author, and is the one accompanying this articla 



Ont 



figures, the protu 



ped together. The observa- 

 tions were uU'made in 1870, and severally at the following times: 

 ^0. 1, Aug. 12, 11''; 2, Feb. 26, 10" 40'"; 3, Jan. 4, l'' 15'^; 4, 

 ^ct 7, 2" uO'" ; 5, Sept. 5, 1"; 6, July 23, 10'' ; 7, Jan. 17, 3" 45™; 

 ll ^ox. 12, 10" 20'^'; 9, Nov. 25, 9" 45™; 10, Jan. 24, 12" 40">; 11, 

 Oct. 25, 10" 40"^; 12, Dec. 2, 1"; 13, Aug. 26, 6" 15"' ; 14, Oct. 29, 

 l2h.3o»'; 15^ Oct. 2 9" 46'"- 16 Nov. 24, 3" 48"' ; 17, March 11, 

 J' 4f ; 18, July 'so, 9" 16-'; 19, Aug. 24, 12"; 20, July 1,2" 25"'; 

 21, Oct. 28, 1" 24'" ; 22, April 18, 10" Y"' ; 23, Aug. 23, 10". 



tie ShorT?'°'' '' '""'^'"^^ ^* '^'"''''' "''^*'r%lSra't™snodS 



'^"ot generSry"!'^ bwrAhr^e'^pLtrbralnnd tlTeTu'rrounding T^","' ""tWof 

 tiesameT ''''''^' ^^'' ^"^ ''' ^"*' '"'''''' a photograph «f " * J^^'^P^^Ig^f J^ced^n a 

 >ot appeared funnel-sh .ped, the central portion being ^|^^^f j'.-^J^j'jj' 

 that thereis sometimes decided evidence of a dow-nward motion, 

 Pubi;:;T P"^*^°" «f ^ ^P«t- I" the remarkable article, P^^/^^^ Jl bl'r vera 

 S?ee d" ^^^^ ^^"" ^^''^'•' ^''^- ^^^^' ^'''^- ^"^'°'' ''^'' h ding^p^rt^ 



T^e 4t\T"hlh the'u JSIJ'LI LlTa'ceTtiXart^^^^^^^^ 1« 



^"«. Stewart, Lcewy), partly by indirect ( 



