ASTRONOMICAL PROGRESS AND PHENOMENA. 



tempted here ; but it may be said that, since 

 the publication of the report of the observers 

 of the eclipse of Aug. 29, 1886, Mr. Huggins 

 himself has grave doubts regarding their re- 

 ality. If they are real, tben during a partial 

 eclipse his plates ought to show the corona 

 partly cut off by the advancing and receding 

 moon. Upon photographs taken at the Cape 

 of Good Hope during the partial phase of the 

 eclipse of Aug. 28, 29, 1886, this cutting off of 

 the corona is not shown. After receiving this 

 announcement, Mr. Huggins, in a published 

 letter, says : " I wish to be the first to make 

 known this untoward result. I greatly regret 

 that a method which seemed to promise so 

 much new knowledge of the corona, would 

 seem to have failed." Mr. Commons, a dis- 

 tinguished celestial photographer, does not 

 share in Mr. Huggins's adverse and perhaps 

 prematurely expressed opinion. 



Photometry. This comparatively new branch 

 of astronomical research was inaugurated in 

 this country by Prof. E. C. Pickering, of Har- 

 vard College Observatory, who has prosecuted 

 it with marked success. He uses an instru- 

 ment of his own invention, called a " meridian 

 photometer." Briefly, it consists of a horizon- 

 tal telescope having two similar object-glasses 

 of four centimetres aperture, with a right-angle 

 prism in front of each. The north star, which 

 is used as the comparison star for all others, is 

 reflected through one prism, and the star under 

 investigation through the other. By motion 

 given to the prism, the images of the stars are 

 brought close together in the same field of 

 view, for easy comparison and accurate results. 

 In front of the eye-piece is a Nicol prism and 

 a small graduated circle. When the former is 

 rotated from the point where one image disap- 

 pears, the light of that image will be propor- 

 tional to the square of the sine of the angle, 

 which may be measured very exactly by an 

 index attached to the graduated circle. The 

 magnitude of the work accomplished by this 

 instrument was not appreciated by astrono- 

 mers until the publication of Part I of vol. 

 xiv of the annals of that observatory, contain- 

 ing the results of the director's photomet- 

 ric examinations of all naked-eye stars to 30* 

 of south declination, amounting in number to 

 4,260, representing 94,476 separate compari- 

 sons, and involving an amount of labor that 

 none but a participator can estimate. Because 

 of the elegance of its methods and complete- 

 ness of its work, the inventor was induced to 

 construct a larger photometer with which to 

 observe stars down to the tenth magnitude, 

 and even some of the asteroids, to determine 

 whether they, as some have thought, are va- 

 riable in brightness. Several astronomers in 

 Europe, notably Rev. Charles Pritchard, D. D., 

 Savilian Professor at Oxford, have done suc- 

 cessful work in the same line, though the 

 instrument used, called a wedge photome- 

 ter, differs from that of American invention. 

 Though not quite equal in accuracy to that of 



Harvard, Dr. Pritchard claims for it exactness 

 to the one tenth of a magnitude. 



The Biela Star-Shower. That there is a star- 

 shower, in this age, occurring on the morning of 

 Nov. 14, and that it is associated with a long- 

 period comet (Tempel's) are truths somewhat 

 universally recognized; but that there is also 

 another November shower, sometimes of great 

 brilliancy, which occurs on the evening of the 

 27th of that month, and is also connected with 

 a comet (Biela's), is not so extensively known. 

 Because of the great shower, observed over 

 more than half of the globe, of Nov. 27, 1872, 

 and also that of 1885, it is appropriate that a 

 brief history of the comet, its rupture, its final 

 loss, and the periodical star-shower resulting 

 from the disintegration, be given. It was first 

 discovered on March 8, 1772, by Montaigne, 

 who did not suspect its periodicity. It was 

 not again seen until Nov. 10, 1805, when it 

 was rediscovered by Pons. Elliptic elements 

 were calculated by Bessel, though it was not 

 associated with any previous comet. On Feb. 

 27, 1826, Biela discovered a comet for which 

 calculation indicated an elliptic orbit of short 

 period, and, furthermore, that it was identical 

 with the comet of the years 1772 and 1805, and 

 would be again due in 1832, which prediction 

 was verified to the letter, the comet returning to 

 perihelion within twelve hours of its computed 

 time. At its next return it was not found ; 

 but in 1846, being well situated for observa- 

 tion, it was early detected and watched with 

 great interest. A few weeks after the discov- 

 ery, the strangest phenomenon in the annals of 

 cometary astronomy viz., its disruption into 

 two comets was witnessed. The cometary 

 pair traveled through space side by side, the 

 distance between them increasing until, on 

 Feb. 9, 1846, a maximum distance of 227,000 

 miles was reached, which, at its next return in 

 1852, had grown to 1,250,000 miles. Since 

 then it has not been observed, nor will it 

 probably ever again be seen. Whether the dis- 

 integration has been complete, is unknown. 

 Thus the matter rested, and was partly forgot- 

 ten, until Nov. 27, 1872, when the world, and es- 

 pecially the Eastern Continent, was startled by 

 a star-shower equal to any ever seen in Europe 

 (though far inferior to the great shower observed 

 on this continent on the morning of Nov. 13, 

 1833). It was soon ascertained that the rain of 

 meteors was caused by the passing of the earth 

 through the debris of Biela's comet. In Eng- 

 land they fell at the rate of 10,000 an hour, as 

 seen from any one station. The radiant was 

 in Andromeda, On Nov. 27, 1885, the Biela 

 meteoric shower repeated itself; and, as in the 

 case of its predecessor, the Eastern was the 

 favored continent, though the display in this 

 country was sufficient to attract general atten- 

 tion. At the Glasgow Observatory the num- 

 ber of meteors visible during one hour and 

 fifty minutes was estimated at over 23,000. 

 Throughout Europe and Asia it was an exact 

 counterpart of the shower of 1872. The pas- 



