A. MATHEMATICS AND ASTRONOMY. 7 



their zeal and ability ; and, indeed, the honors of the occasion 

 were fairly shared with their European brethren by the offi- 

 cers of the observatory and their American companions. The 

 present report is accompanied by two plates, exhibiting the 

 appearance of the sun during the eclipse. The general ty- 

 pography of the work does the fullest credit to the national 

 printing-office, from which it emanated. 



FUTURE ECLIPSES OF THE SUN. 



Mr. Robert T. Paine communicates to SUUmarCs Journal a 

 list of eclipses visible in the United States during the re- 

 mainder of this century. The first central eclipse will be 

 that of September 29, 1875, which will be annular in part of 

 the State of New York and in four of the New England 

 States. The duration of the ring on the central line will be 

 three minutes thirty-nine seconds. At Boston it will be only 

 two minutes twenty-nine seconds. The belt of country over 

 which the annular eclipse will extend will be 110 miles wide. 

 Within it are situated the observatories of Hamilton College, 

 Albany, Harvard University, Amherst College, and Dart- 

 mouth College. The first total eclipse will be that of July 

 29, 18 78, when the shadow of the moon will pass over British 

 Columbia, Montana, Colorado, Texas, and Cuba. At Denver, 

 Colorado, the eclipse will be total nearly three minutes. 



MOVEMENT OF STARS IN SPACE. 



General Dufour, of Switzerland, in the course of a recent 

 investigation, attempts to show that in the case of the move- 

 ment of two stars around a point supposed fixed, this point 

 must be in motion. He also concludes that the curve is plane, 

 and that the stars remain in the same plane during their 

 translation ; and the inference is that these stars have both 

 received one impulse and a parallel movement ; also that the 

 movement of the apsides proves that the centre of gravity of 

 the system is displaced, not according to a straight line, but 

 a curved one. Mem. Soc. Phys. de Geneve, XXL, 1870, 344. 



IS THERE A RESISTING MEDIU.M IN SPACE ? 



Professor Asaph Hall, at a late meeting of the Philosoph- 

 ical Society of Washington, presented a communication (since 

 published in Sillimarts Journal) on the astronomical proof of 



