Page:Popular Science Monthly Volume 92.djvu/897

 When the Moon Darkens the Sun

What astronomers will look for during the June total eclipse of the Sun

Bv ('al\in Fr;iZ(M-

��A TOTAL eclipse of the sun is one of the most awe-inspiring spec- tacles in the whole repertory of Nature. Its overpowering effect upon the human mind is illustrated by an episode which the present writer recalls in connection with the eclipse of May 28, 1900, as seen at Norfolk, Vir- ginia. The weather was superb, and the town was crowd- ed with visitors: besides whom the natives were all on the streets. During the period of about an hour following "first contact," while the disk of the moon encroached more and more upon the face of the sun, the spec- tators, white and black, kept up a lively chatter of conversation. Probably most of them found the phenomenon rather tame, and wondered why people should travel miles to see it. Just be- fore the beginning of totality the light of day faded with startling abruptness, the beautiful solar corona flashed out, the stars appeared in the sky, and a ruddy glow, as of late sunset, encircled the horizon. The babel of conversation ceased instantly, and was succeeded by the crash of breaking glass. Totally un- prepared for so marvelous a sight, many people, especially among the colored population, let fall the pieces of smoked or tinted glass through which they had been \iewing the eclipse!

Interesting to the layman as a spec- tacular event, a total solar eclipse is even more interesting to the astronomer as a rare opportunity for obtaining fresh

���Renewed efforts will be ir.c^c qL liic com- ing eclipse to solve the mystery of the flickering "shadow bands," which steal over the ground at the beginning and end of totality. Former attempts to photo- graph these "flickerings" were not successful

��light on a wide range of scientific prob- lems. Hence, in order to observe a proc- ess of Nature lasting generally only two or three minutes e.xpeditions are or- ganized and equipped at great expense, and sent perhaps halfway 'round the world to some favorable vantage point. After arrival, many weeks are spent in setting up and ad- justing instruments and rehearsing every detail of the observations, so that the advance program may be carried out with- out a hitch at the proper time. Every precaution is ta- ken to economize to the utmost the precious seconds available during the event.

After all these preparations, the astronomers in many cases get no results at all, ow- ing to unfavorable weather. A single cloud may blast their hopes. The party sent from the Lick Observatory to view the eclipse of 1900 encountered a citizen of Georgia who was frankly skeptical about their ability to foretell the occurrence of the eclipse, and his doubts deepened to positive dis- belief when he heard the observers anxiously speculating about what the state of the weather might be on the eventful day. "These young men," he said, "try to tell me they know the sun is going to be eclipsed, and they can't even tell whether the sky is going to be clear!"

fnfortunately the only help the mete- orologist can give to the astronomer in this matter is to tell him what the average weather has been in previous years on the

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