ASTRONOMICAL PROGRESS AND PHENOMENA. 



41 



physical changes in the sun, but from the effect 

 of temperature on the instruments, and from 

 difference in the quality of the telescopic 

 images at opposite seasons of the year. An- 

 other discussion of the horizontal diameter of 

 the sun has been made by Prof, di Legge from 

 meridian transits of the sun observed at Campi- 

 doglio from 1874 to 1883. The mean horizontal 

 diameter at mean distance deduced from 5,796 

 transits by four observers on 2,213 days is 32' 

 02-38". From May, 1876, the sun's transit has 

 been observed by projection, thus enabling two 

 or more persons to observe simultaneously, 

 and thereby affording exceptionally favorable 

 opportunities for the determination of personal 

 equation. 



Prof. John Trovvbridge and Mr. C. 0. Hutch- 

 ins have recently investigated the solar spec- 

 trum with very powerful apparatus, and they 

 find that the alleged bright bands, upon which 

 Dr. Henry Draper based his so-called discovery 

 of oxygen in the sun, do not exist. They have 

 also examined Prof. J. 0. Draper's hypothesis 

 of the coincidence of certain dark lines in the 

 solar spectrum with the lines in the spectrum 

 of oxygen, and find it equally destitute of any 

 physical basis. 



Total Solar Eclipse of Angnst 19, 188T. This 

 eclipse excited the greatest interest through- 

 out Europe, and will be memorable as the first 

 during which attempts were made to observe 

 and photograph the corona from balloons. At 

 Berlin the totality began at 5'05 A. M., and as 

 there were few favorable points for observa- 

 tion within the city, the people flocked by tens 

 of thousands out into the open country, whither 

 they were conveyed by special trains, steam- 

 boats, and vehicles innumerable. The princi- 

 pal streets of the city were more thronged 

 from 2 to 4 A. M. than they usually are at 

 midday, and the Tempelhof field never held a 

 larger crowd during a grand review than at day- 

 break on the morning of the eclipse. Most of 

 the people obtained only momentary glimpses 

 of the partial phases; but those at Hoppe- 

 garten, ten miles east of Berlin, were more 

 highly favored. There the totality was con- 

 cealed only by a thin veil of clouds, through 

 which both the chromosphere and the corona 

 were visible; but unfortunately no skilled ob- 

 servers were present. While totality lasted, the 

 darkness was so great that it was hardly possi- 

 ble to recognize faces at a yard's distance. 



In Russia, quite unprecedented preparations 

 were made for the occasion, and, had the 

 weather been favorable, this eclipse would 

 have been observed and investigated there in 

 the most thorough manner. An intelligent 

 taste for scientific work is very widely spread 

 among educated Russians, and their enthusiasm 

 on this occasion may be imagined from the 

 sale in Moscow alone of 145,000 glasses and 

 400,000 descriptive pamphlets. Enlightened 

 by this surprising quantity of popular litera- 

 ture, the Russians of all classes flocked in great 

 numbers to many points of observation. For 



the first time in Russia, an excellent service of 

 cheap excursion -trains was organized, with 

 traveling comforts such as are only to be had 

 on the great trunk-lines. Even the Grand 

 Duke Constantine, who selected Tver as his 

 point of view, did not disdain to travel by a 

 special train of this class on the Nicholas Rail- 

 way. During the night preceding the eclipse, 

 about 300 persons went to Klin from St. Peters- 

 burg, and about 600 more from Moscow. The 

 Physical Society of St. Petersburg distributed 

 papers, with directions for amateur observa- 

 tions, to all passengers in the special train on 

 the Moscow line, but the weather turned out 

 so badly that probably not one of the blanks 

 was filled out by the disappointed enthusiasts. 

 Among the visitors to Russia were many dis- 

 tinguished foreign astronomers, all of whom 

 were received with the utmost kindness, and 

 assisted in every possible way. 



The central line of the eclipse first struck 

 the earth at a point 53 miles west-northwest 

 of Leipsic, in latitude 51 38' north, longi- 

 tude 11 16' east of Greenwich, where the sun 

 was just rising. From there the line of total- 

 ity, which was about 135 miles wide, sped 

 across Germany, Russia, Siberia, China, and 

 Japan, and finally left the earth at a point in 

 the Pacific Ocean, in latitude 24 27' north, 

 longitude 173 30' east., where the sun was 

 just setting. The actual distance traveled by 

 the shadow was about 7,960 miles, and the 

 time occupied was 2 h 42 12', whence the 

 average rate of motion was 49 miles a minute, 

 say fifty times that of an express train, or 

 twice that of a shot from a modern, high-pow- 

 ered, rifled gun but the speed was consider- 

 ably less near the middle of the path, and 

 greater toward its ends. The entire duration 

 of the partial phase of the eclipse upon the 

 earth's surface was 4 h 53 m 24'. In Germany 

 the sun was too low during totality for ad- 

 vantageous photographic and spectroscopio 

 work, and for such observations it was neces- 

 sary to go farther east. The best localities 

 were in Eastern Siberia, about latitude 50 30' 

 north, longitude 112 east, but, as it was prac- 

 tically impossible to transport heavy instru- 

 ments beyond the Ural mountains, and in the 

 immediate neighborhood of these mountains 

 the meteorologists thought it likely to be 

 cloudy, nearly all the best equipped parties 

 were concentrated between Moscow and St. 

 Petersburg. This proved most unfortunate, for 

 speaking generally, during the eclipse, the sky 

 westward of the Ural mountains was overcast, 

 while eastward it was beautifully clear. The 

 neighborhood of Moscow and Tver, of which 

 the meteorologists spoke highly as regards the 

 chances of fine weather, was shrouded in 

 clouds and mist, while Yekaterinburg, which 

 they had comparatively condemned, was re- 

 joicing in a clear sky. And, whereas the early 

 morning hours, in which the eclipse took place, 

 are more generally fine than the corresponding 

 evening hours, it so happened that in the 



