64 Mr. J. N. Lockyer on the recent Solar Discoveries. 



to hold to that statement instead of the contrary one ; but my 

 remark simply meant that if the chromosphere were thin instead 

 of thick, that is, if it did not extend to the photosphere, there 

 would be less room for pressure to make itself evident. He 

 then adds, " cette structure des masses suspendues dans une at- 

 mosphere resulte des observations des eclipses." 



Here I would ask where such observations of the chromosphere 

 (for the prominences are not in question) are recorded, and how 

 such observations, if they exist, could help us in such a question. 

 I next read, " il est impossible d'admettre que ces images ou 

 ces colonnes inclinees puissent rester suspendues, sans un milieu 

 qui les supporte et qui soit different d'elles-memes." The re- 

 ply to this is, that if Father Secchi or any one will prove the ex- 

 istence of this medium, I will willingly admit it ; but I have to 

 bear in mind : — 



I. That although Dr. Frankland and myself have shown that 

 the temperature is high enough in the prominence-region to 

 render other substances incandescent, if they were there, we 

 have no spectroscopic evidence of their existence. 



II. That the tenuity of the prominences is excessive. 



III. That the prominences are not static, but are rapidly 

 driven beyond the upper level of the chromosphere, and as ra- 

 pidly vanish. 



IV. That there is no cooler hydrogen above the chromo- 

 sphere, or we should get the F line alone. 



V. That hydrogen is the lightest gas. 



Father Secchi claims my observations of the injections of so- 

 dium, magnesium, &c. into the chromosphere as supporting the 

 existence of his continuous-spectrum-giving stratum below the 

 chromosphere. I ask how is this possible ? Moreover my obser- 

 vations show, I think, that the vapours of sodium, magnesium, 

 &c. lie immediately below the photosphere ; and how can they 

 there give a continuous spectrum if they do not above and do 

 not below ? 



In my former paper I said that, by using three prisms, the spot- 

 phenomena were possibly as complicated as Father Secchi has 

 described them, but that with my greater dispersive powers this 

 complication vanishes to a great extent. On this Father Secchi 

 states that 1 " cherche a mettre mes resultats en opposition avec 

 les siens." Remarking that my object was the very opposite, I 

 again quote from one of Father's Secchi' s latest papers*, a later 

 one than that in which he states that the spectrum of a spot is 

 similar to the spectrum of the limb : — " II n'y a pas production 

 des raies fondamentales nouvelles, mais seulement un renforce- 

 ment considerable des raies solaires connues comme dejk exis- 

 * Comptes Rendus, 1869, 2 e sera. p. 166. 



