34 SCIENCE IN SHORT CHAPTERS. 



second, not merely a closed but even an absolutely circular 

 orbit would be possible. These and the multitude of weaker 

 lateral ejections, reaching the sun by short parabolic paths, 

 explain the mystery of the inner corona. 



I need only refer Mr. Proctor to his own recently pub- 

 lished book on the Sun, where he will find on plates 4, 5, 

 and 6 a number of drawings from Zollner and Respighi, 

 which so thoroughly confirm my necessary theoretical de- 

 ductions that they might be a series of fancy sketches of 

 my own. When we consider that the base of a prominence 

 is only visible when it happens to start exactly from the 

 limb of the sun, while the vastly greater proportion of those 

 which are observed, and have been drawn, have much of 

 the stem cut off from view by the solar rotundity, the evi- 

 dence afforded by such drawings in support of my the- 

 oretical deduction, that the typical form of the solar promi- 

 nences is that of a palm-tree or bursting rocket, is greatly 

 strengthened.* 



In a paper by P. Secchi, dated Rome, March 20, 1871, 

 and published in the " Comptes Rendus," March 27, this 

 veteran solar observer speaks of the prominences as com- 

 posed of jets, which, "upon reaching a certain elevation, 

 stop and whirl upon themselves, giving birth to a brilliant 

 cloud." This cloud is represented as spreading out on all 

 sides from the summit of the combined jets. Again he 

 says, "It is very common to see a litte jet spot at a certain 

 elevation above the chromosphere, and there spread itself 

 out into &ivi'de hat (" un large cha-peau") of an absolutely 

 nebulous constitution." This outspreading nebulosity is 

 the flash of the incandescent vapors produced by the ex- 

 plosion which is theoretically demanded by my explanation 

 to occur exactly in the manner and place described. These 

 expanded incandescent gases will be rendered visible by 



* Any reader of ' ' The Fuel of the Sun" will perceive that the vapor- 

 ous envelope which I have described as "an effectual jacket for limit- 

 ing the amount of radiation," is a complete theoretical anticipation 

 and explanation of the "solar crust" of Respighi and the "Tren- 

 nungschicht" of Zollner. We agree perfectly in our conclusions, 

 though arriving at them by such very different paths, and so inde- 

 pendently of each other. 



