1871.] The Fuel of the Sun, 457 



the path of any of the planets by establishing itself in 

 an orbit constantly intermediate between any two. Having 

 once settled into such a path, it would remain there with 

 comparative stability and permanency. If I am right in 

 this view of the dynamical history of these older ejections, 

 all the long elliptical paths of zodiacal particles, meteorites, 

 or asteroids, would thus in the course of ages become 

 eliminated, and the remaining orbits would be of planetary 

 rather than cometary proportions." 



A little reflection on the above-stated laws of dis- 

 sociation will show that the maximum violence of 

 hydrogen explosion will not occur at the birth of the 

 ejections, but afterwards, when the dissociated gases have 

 been already hurled beyond the sphere of restraining 

 vapours. If my explanation is correct, the typical form of a 

 solar prominence should be that of a spreading tree with a 

 tall stem. At first the least resistance to radiation and con- 

 sequent explosive combination must be in the vertical 

 direction, as this will afford the shortest line that can be 

 drawn through the thickness of the surrounding jacket 

 of resisting vapour ; but when raised above this en- 

 velope, the dissociated gases cooled by their own expan- 

 sion and comparatively free to radiate in all directions 

 except downwards, will explode laterally as well as ver- 

 tically, and thus spread out into a head. My theoretical 

 prominence will be, in short, a monster rocket proceeding 

 steadily upwards to a certain extent, and then 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 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 

 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 drawings in support of my 

 theoretical deduction, that the typical form of the solar 



