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THE SOLAR ECLIPSE OF JULY *$ , 1878. 265 



curious and important phenomena connected with it. Much interest was attached 

 to the eclipse by scientists, who looked upon it as the means of determining many 

 vexed questions. First, and perhaps the most important, as it is of practical 

 value to the navigator, were the corrections to be obtained to the present solar 

 and lunar tables. Notwithstanding the remarkable accuracy already obtained, 

 the location of the central line of the eclipse, as calculated by the American 

 Nautical Almanac, differs by about four miles from that derived from the English 

 Nautical Almanac. Important observations were also to be made respecting the 

 physical constitution of the sun. The polariscope and the spectroscope were 

 used to examine the corona of the sun during totality. As the duration of totality 

 was not more than three minutes in the North, and two and a half in Texas, all 

 the observers were required to work very rapidly in order to obtain the desired 

 observations. 



Advantage was taken of the sun's obscuration by the dark moon to examine 

 the heavens in the neighborhood of the sun for Vulcan and one or more other 

 small bodies that might be added to our solar universe. Besides this careful 

 telescopic scrutiny, large photographs were taken of the heavens, in order to 

 allow the small planets, if any there be, to print themselves upon the photographic 

 plate, and thus announce to the world the fact of their existence and their influence 

 upon the motions of their neighbor, Mercury. 



The results of all these observations were reported to the Chicago Tribune, 

 by Prof. Colbert, of the Chicago University, as follows: 



The Chicago Astronomical Society observed from Capitol Hill, in Denver, 

 commanding a magnificent view of the mountains to the northwest. 



The first contact was at 2h. 19m. 3o^s. , local time. The second at 3I1. 

 28m. 3'J4s. The duration of the totality was 2m. 4o^s., being 3^'s. less than 

 the computed time. The last contact was at ah. 35m., which shows that the 

 moon's path was further south than calculated, or her diameter was estimated 

 too large. We looked vainly for Vulcan, but there was too much light to see a 

 small object so far away. 



Prof. Thomas saw the line numbered 1,474, in the spectrum of the corona, 

 but no new lines. The corona was much smaller than usual and measured an 

 average of 26 minutes of arc from the moon, or 700,000 miles high. It was very 

 pale, almost white. The corona was strongly striped in spiral rays thirty degrees 

 from the direction of the radius. It flared most markedly in the direction of the 

 ecliptic. Prof. Hough saw the chromosphere, extending some 3,000 miles from 

 the sun's normal surface. There were very few protuberances and they were 

 very pale. Two on the western side of the sun were the largest. 



The scarcity of the red flames tends to confirm the theory of connection with 

 the sun spots. This is near the minimum of the spots, 



A class of about twenty citizens made drawings in this section, which will be 

 ^compared and averaged at the Dearborn Observatory. Hawkins, of Denver, took 

 several instantaneous pictures with the camera, which develop well and are very 

 valuable. 



