On the Temperature and Physical Constitution of the Sun. 343 



we have 



, 8 64000 



(u— vy= — pj — = 78o45, 



m-v=280, 

 or 



w=250, 

 since 



r = 30 nearly. 



Hence with lead the velocity must be about eight times as great 

 as with glass. 



XLIII. On the Temperature and Physical Constitution of the 



Sun. (Second Memoir.) By F. Zollner. 



[Concluded from p. 304.] 



§7. 



IF M. Faye has recently started the question why the masses 

 of hydrogen perpetually hurled aloft, through eruptive pro- 

 tuberances, from the interior of the sun have during the last 

 thirty years not perceptibly augmented the chromosphere*, the 

 above-given numerical values will suffice to answer this question, 

 on the supposition of its premises, in accordance with the observa- 

 tions. Apart, however, from this, even the hypotheses on which 

 alone M. Faye's question can have any meaning seem to me to 

 be in direct contradiction to the view he has so often and so 

 strenuously maintained, of the preponderantly gaseous constitu- 

 tion of the body of the sun ; for the augmentation of the atmo- 

 spheric envelope of a heavenly body through eruptions of gas 

 from its deeper-lying parts is inconceivable unless the space 

 whence the gas issues is enclosed by an envelope impervious to 

 the outer atmosphere. But if such an envelope does not exist, 

 or if the then unknown processes of eruptive-protuberance deve- 

 lopment take place outside the envelope and therefore in the 

 lower strata of the atmosphere itself, the total quantity of this 

 atmosphere can neither be increased nor diminished; for the 

 volumes of gas thrown up are only portions of the atmosphere 



* Vide Comptes Rendus, vol. lxxv. p. 1669 (Dec. 16, 1872) :— "I have 

 often asked myself whence came the hydrogenated flames of the chromo- 

 sphere, which seem to be produced by continual violent eruptions. If the 

 hydrogen issues unceasingly from the interior, how is it that it has not in- 

 creased during the thirty years that protuberances, and even traces of the 

 chromosphere, have been observed in eclipses, and during the three years 

 that the chromosphere has been followed day by day ? If it is not expelled 

 beyond the sphere of the sun's action, it must, notwithstanding its specific 

 lightness and the total absence of all indications of descending currents, in 

 some way reenter the body of the sun." 



