[Illustration:  Fig. 32.—­The Corona in 1858, Brazil.]

It was then settled that the corona consists of reflected light, sent to us from dust particles or meteoroids swirling in the vast seas, giving new densities and [Page 83] rarities, and hence this changeful light.  Whether they are there by constant projection, and fall again to the sun, or are held by electric influence, or by force of orbital revolution, we do not know.  That the corona cannot be in any sense an atmosphere of any continuous gas, is seen from the fact that the comet of 1843, passing within 93,000 miles of the body of the sun, was not burned out of existence as a comet, nor in any perceptible degree retarded in its motion.  If the sun’s diameter is to include the corona, it will be from 1,260,000 to 1,460,000 miles.

[Illustration:  Fig. 33.—­The Corolla in 1878, Colorado.] [Page 84] Come closer still.  At the instant of the totality of the eclipse red flames of most fantastic shape play along the edge of the moon’s disk.  They can be seen at any time by the use of a proper telescope with a spectroscope attached.  I have seen them with great distinctness and brilliancy with the excellent eleven-inch telescope of the Wesleyan University.  A description of their appearance is best given in the language of Professor Young, of Princeton College, who has made these flames the object of most successful study.  On September 7th, 1871, he was observing a large hydrogen cloud by the sun’s edge.  This cloud was about 100,000 miles long, and its upper side was some 50,000 miles above the sun’s surface, the lower side some 15,000 miles.  The whole had the appearance of being supported on pillars of fire, these seeming pillars being in reality hydrogen jets brighter and more active than the substance of the cloud.  At half-past twelve, when
 Professor Young chanced to be called away from his observatory, there were no indications of any approaching change, except that one of the connecting stems of the southern extremity of the cloud had grown considerably brighter and more curiously bent to one side; and near the base of another, at the northern end, a little brilliant lump had developed itself, shaped much like a summer thunderhead.

[Illustration:  Fig. 34.—­Solar Prominences of Flaming Hydrogen.]

But when Professor Young returned, about half an hour later, he found that a very wonderful change had taken place, and that a very remarkable process was actually in progress.  “The whole thing had been literally blown to shreds,” he says, “by some inconceivable uprush from beneath.  In place of the quiet cloud I had [Page 87] left, the air—­if I may use the expression—­was filled with the flying debris, a mass of detached vertical fusi-form fragments, each from ten to thirty seconds (i. e., from four thousand five hundred to thirteen thousand five hundred miles) long, by two or three seconds (nine hundred to thirteen hundred