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THE POPULAR SCIENCE MONTHLY.— SUPPLEMENT. 



served, which certainly belonged to the sun, 

 many astronomers, and especially those called 

 professional astronomers (that is, persons em- 

 ployed in timing the motions of the heavenly 

 bodies), were unwilling to believe that anything 

 astronomical was in question. They struggled 

 for a time to show even that the colored promi- 

 nences do not belong to tbe sun at all. They 

 ridiculed the idea that observations of these " ap- 

 pendages" could be of any value compared with 

 time observations, measurements of the cusps of 

 the solar crescents, etc. — such observations, in 

 fine, as might serve to correct the moon's motions 

 by a few seconds. 



At present all this is changed. Some profes- 

 sional astronomers there still are who would 

 rather see the study of solar eclipses restricted to 

 time observations and geometrical measurements, 

 just as they would limit our study of transit ob- 

 servations to noting the moments of internal and 

 external contact. But the great body of astrono- 

 mers have learned to recognize the far greater 

 interest and (even in the scientific sense) the far 



and is, moreover, in its own non-astronomical way, so 

 interesting, that I venture to quote the greater part 

 of it: "As the sun obfuscated, the air sensibly cooled, 

 the atmospberic light became mellowed, deepening to 

 a darkness which bore no resemblance either to morn- 

 ing or evening twilight, and at the greatest obscuration 

 assumed the peculiar lurid gloom which commonly 

 heralds in a summer thunderstorm. Mercury was now 

 seen in the finder, and Venus with the naked eye, but 

 the time of her earliest visibility was omitted to be 

 noted. Tbe effect on the temperature was more re- 

 markable than on the light, a difference which may be 

 ascribed to the effect of radiation. The vegetation in 

 a line with the sun assumed a silvery purplish hue, 

 and in the shade an orange tinge; while the crocus, 

 gentian, and anemone, partially closed their flowers, 

 and reopened them as the phenomena passed off; and 

 a delicate South African mimosa, which we had reared 

 from a seed, entirely folded its pinnate leaves until the 

 sun was uncovered. More than one person took no- 

 tice that, while the temperature was at its lowest scale, 

 the earthworms crept from their boles; and, among 

 other remarks made by friends during the eclipse, I 

 may mention a very striking though well-known 

 optical property. One was looking at the eclipse from 

 near a tree, the shadow of which was cast on a white, 

 dead wall. Turning his back to the sun, he perceived 

 the shade from the leaves, where, under ordinary cir- 

 cumstances, each littlo interstice is a complete circle 

 assuming the crescent shape as the eclipse progressed, 

 waxing, waning, and shifting the cusps, thus affording 

 a perfectly reflected image of the whole phenomenon." 

 There is even extant a series of instructions issued by 

 the present astronomer royal for the observation of a 

 solar eclipse, in which all the suggested observations, 

 save one alone, arc directed to phenomena which at 

 the present time are regarded as utterly unworthy of 

 attention compared with those bearing on solar re- 

 search 



greater importance of physical observations. All 

 that has been done in the last century, in the ac- 

 curate measurements of the motions of the moon 

 and planets by eclipses and transit observations, 

 is of incomparably smaller real scientific interest 

 than the recognition of the single fact that the 

 sun's whole frame is enwrapped in glowing gas. 

 Apart, too, from the mere question of scientific 

 interest, the attention given to those matters by 

 those who are not professed students of science 

 is a matter of considerable moment, seeing that it 

 largely influences the progress of human thought 

 and therefore the well-being of the human race. 

 Now, the general public refuses (and very natu- 

 rally) to take the least interest in the geometrical 

 relations involved in the theory of eclipses. It is 

 very little interested if it is informed that at such 

 and such an eclipse the moon's motions were cor- 

 rected by so many seconds, and that tbe recogni- 

 tion of such and such a discrepancy may proba- 

 bly lead to the detection of some as yet unnoticed 

 perturbation. But the series of physical discov- 

 eries which have been made during recent eclipse 

 observations, the recognition of the colored prom- 

 inences and their interpretation, the solution of 

 the problem presented by the solar corona, and 

 the remarkable series of researches which have 

 been directly led up to by those eclipse observa- 

 tions — all these have been followed with eager 

 interest by the general public. I cannot but 

 think that, in the preference they have just shown 

 for solar discoveries, and the comparative disre. 

 gard of merely geometrical relations, the general 

 public has shown excellent judgment. 



Passing over the eclipse of 1848, in which the 

 colored prominences were first fairly recognized, 

 that of 1859, in which they were shown to belong 

 to the sun, and that of 1860, in which De la Rue 

 and Secchi photographed them, we come to the 

 great Indian eclipse of 1868, in which for the 

 first time their true nature was recognized. They 

 were found to be vast masses of glowing vapor 

 surrounding the sun on all sides, but extending 

 in mighty flames at certain points to enormous 

 distances from his surface. 



In the interval between the great eclipse and 

 the eclipse of 186°, a method was devised for 

 observing these colored flames when the sun is 

 not eclipsed, and not only of observing them, 

 but of analyzing them, determining what gases 

 are present in them, and even in what condition 

 such gases subsist, and the changes of condition 

 they undergo. I say that this method was de- 

 vised in the interval ; but it would be more cor- 

 rect to say that it was then first successfully ap- 



