96 SCIENCE IN SHORT CHAPTERS. 



a head. My theoretical prominence will be, in short, a monster 

 rocket proceeding steadily upward to a certain extent, and 

 then gradually bursting and projecting its missiles in every 

 direction from the vertical to the absolutely horizontal. 

 Should the latter acquire a velocity of about 300 miles per 

 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 shoit parabolic paths, 

 explain the mystery of the inner corona. 



I need only refer Mr. Proctor to his own recently published 

 book on the sun, where lie will find on plates 4, 5, and 6 a 

 number of drawings from Zollner and Respighi, which so 

 thoroughly confirm my necessary theoretical deductions 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 evidence afforded by such diawings in 

 support of my theoretical deduction, that the typical foim of 

 the solar prominences is that of a palm-tree or bursting rocket, 

 is greatly strengthened.* 



In a paper by P. Sccclii, dated Rome, March 20th, 3871, 

 and published in the Comptes Rendus, March 27th, this veteran 

 solar observer speaks cf the pi eminences as composed 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 

 little jet stop at a certain elevation above the chromosphere, 

 and there spread itself out into a wide hat (" un large 

 chapeau") of an absolutely nebulous constitution." This out- 

 spreading nebulosity is the flash of the incandescent vapors 

 produced by the explosion which is theoretically demanded by 

 my explanation to occur exactly in the manner and place 

 described. These expanded incandescent gases will be render- 



* Any reader of Tlie Fuel of the Sun will perceive that the vaporous 

 envelope which I have described as "an effectual jacket for limiting 

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

 explanation of the "solar crust" of Eespighi and the "Trennung- 

 schiokt" of Zollner. We agree perfectly in our conclusions, though 

 arriving at them by such very different paths, and so independently 

 of each other. 



