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SCIENTIFIC SUMMARY. 
ASTRONOMY. 
^HE Eclipse of August 7. — The successful obseryation of this great total 
eclipse by the American astronomers is undoubtedly the most important 
astronomical event of the past quarter. The study of solar’physics has re- 
cently made such rapid progress, and facts of such importance have come to 
light, that greater attention is attracted towards eclipse-observations than 
at any former epoch. The circumstances of the [recent] eclipse were of the 
most favourable character. The moon’s shadow traversed the United States 
along a course which brought the line of central eclipse close by many of 
the most important observatories. Then the weather was all that could be 
desired, so that not one of the observing parties, so far as is yet known, lost 
any part of the totality. Again, the peculiarities on which the darkness 
during totality depends were all, it would seem,7n favour of the observers. 
Few circumstances are more perplexing than the different degrees of dark- 
ness observed during total eclipses of the sun. In India, during the great 
eclipse of last year, though the sun was hidden Tor nearly seven minutes, 
the darkness was by no means striking; whereas in America this year, 
although the totality lasted scarcely four minutes, the obscuration was very 
remarkable indeed. The discovery by Professor Winlock that the spectrum 
of a prominence which was visible during the eclipse contained no less than 
eleven bright lines, is perhaps the most interesting result of the eclipse ob- 
servations. It shows that whatever the prominences may be, they are not 
simple hydrogen flames. It is to be hoped that our spectroscopists may be 
able to detect these lines, and so to learn what substances are present in the 
va.«t tongues of flame which spring from the solar photosphere. 
Search for lutra-Mei'curial Planets . — The observers of the eclipse of 
August 7 searched in the sun’s neighbourhood for the planet Vulcan which 
Ix?scarbault is supposed to have discovered. If such a planet as this really 
exist in the sun’s neighbourhood, it should be a very conspicuous object 
during a total eclipse (unless, of course, it happened to be in or near either 
of its conjunctions). The extreme brilliancy of its illumination would more 
than make up for its great distance, even a.ssuming it to be in that part of its 
orbit where it would be further from us than Mercury or Venus at their 
elongations. No sign of Vulcan or of any of its suppo8ed[fellow-planets was 
detected during the recent eclipse, however ; andj thus for the present the 
theory that there are planets within the orbit of Mercury remains in 
abevance. 
