GREAT SOLAR ECLIPSES. 19 



idea of motion. They were evidently to my senses 

 belonging to the sun, and not at all to the moon ; for, 

 especially on the western side of the sun, I observed 

 that the moon passed over them, revealing successive 

 portions of them as it advanced. In conformity with 

 this observation also, I observed only the summit of 

 one on the eastern side, though my friends, observing 

 in adjoining rooms, had seen at least two ; the time 

 occupied by me in observing with the naked eye not 

 having allowed me to repair again to the telescope 

 until the moon had covered one and three-fourths of 

 the other. . . . The first burst of light from the 

 emergent sun was exactly in the place of the chief 

 western flame, which it instantly extinguished.' 



When we consider the actual dimensions of these 

 prominences we are enabled to form some conception 

 of the importance of the problem which they present 

 to astronomers and physicists. The scimetar-shaped 

 protuberance was estimated to extend fully one-twelfth 

 part of the sun's diameter from his surface. His 

 diameter is known to be eight hundred and fifty 

 thousand miles, so that the height of this singular 

 object was fully seventy thousand miles, or nearly three 

 times the circumference of our globe. Consider, again, 

 the long sierra extending around nearly a quarter of 

 the sun's circumference. This sierra was about twenty- 

 five thousand miles high. Now many of my readers 

 have doubtless seen the ranges of the Alps as they 

 appear, when seen from some distant point in clear 

 weather, and they know how imposing is the aspect 



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