46 



ASTRONOMICAL PHENOMENA AND PEOGKESS. 



rect it to the sky near the star, when (gener- 

 ally), in one or two minutes, the needle would 

 resume its original position. In a similar man- 

 ner, twelve to twenty observations of the 

 same star were made, and repeated on other 

 nights. The mean of a number of observations 

 of Sirius, which did not differ greatly from* each 

 other, gave a deflection of the needle of 2 , 

 Regulus gave a deflection of 3, and Pollux of 

 H. No effect was produced on the needle 

 by Castor. In one observation, Arcturus de- 

 flected the needle 3 3 in fifteen minutes. Mr. 

 Hoggins hoped at some future time to resume 

 these Investigations with a larger telescope, and 

 to obtain some approximate value of the quan- 

 tity of heat received at the earth from the 

 brighter stars. He suggests that such observa- 

 tions, if strictly comparable, might be of value, 

 in connection with the spectra of the light of 

 the stars, to help us to determine the condition 

 of the matter from which the light emanates. 



Apparatus for Mapping Stars. Mr. H. M. 

 Parkhurst has invented and described, in the 

 American Journal of Science, an ingenious ap- 

 paratus for mapping the exact right ascension 

 and declination of stars, and also recording 

 their magnitude. By means of it he can map 

 as many as thirty stars a minute in a crowded 

 field, and averages usually, in a night's work, 

 500 an hour. He has found it easy to take a 

 succession of twelve 15-minute maps in se- 

 lected places, varying many degrees in right 

 ascension and declination, in but little over 

 three hours. Usually, by predetermining the 

 order of mapping, he can map six or eight stars 

 in quick succession, without an error exceed- 

 ing two seconds. By the aid of his star-map- 

 per, the inventor discovered a new asteroid 

 (Galatea), September 30, 1862. It had been 

 previously discovered by M. Tempel, in Eu- 

 rope, but that fact was then unknown in the 

 United States. Mr. Parkhurst has also in- 

 vented a photo-mapper, which he uses in con- 

 nection with the other apparatus. 



Asteroids. The number of known asteroids 

 has been brought up from 106 to 109 by dis- 

 coveries during the year. The finding of aste- 

 roids has been so common of late that the 

 scientific journals no longer think it important 

 to record each successive addition to that large 

 celestial family. In honor of the discovery of 

 the 100th asteroid, the French Academy is- 

 sued large medals, bearing upon one face the 

 profiles, in alto-rilievo, of Goldsmidt of France, 

 Luther of Belgium, and Hind of England, 

 three gentlemen who have been remarka- 

 bly successful in looking up new asteroids. 

 Messrs. Peters of Utica, and Watson of Ann 

 Arbor, in this country, have, of late years, 

 done as much as any two European observers 

 in increasing our knowledge of the members 

 of the asteroid zone. 



New Comets. &. Tempel, of Marseilles, dis- 

 ojfered a new comet, October 11, which was 

 Ojjnred at Bonn October 12, at Carlsruhe 

 October 17, and at Leipsic October 23, from 



the results of which observations the following 

 elements were calculated by Mr. J. K. Bond, of 

 Twickenham, England : 



Inclination to Ecliptic, 68.48 '&' 



Loo-, perihelion distance, 0899o 



Heliocentric Motion Retrograde. 



The orbit does not resemble that of any 

 comet previously computed. M. Tempel dis- 

 covered another comet, November 27, in the 

 constellation of Pegasus, K. A. 311 15', Polar 

 Distance 75 44'. The comet is a nebulous 

 mass from 12 to 15 minutes in diameter, having 

 no nucleus, and less luminous at the centre 

 than ou the circumference. It was advancing 

 at the rate of 1 per'day in K. A., and 55' in 

 declination. 



Winnecke's Periodical Comet. Observations 

 upon this comet were conducted at different 

 times between April 13 and June 26, 1869, by 

 Schmidt at Athens, Bruns and his assistant 

 Vogel at Leipsic, Schonfeld at Mannheim, and 

 Wolff at Bonn. The remarkable faintness of 

 its light prevented much being done in the way 

 of physical observation. May 14th, Vogel saw, 

 very distinctly, a tail-like lengthening; and 

 Schmidt remarked a small trace of a tail on 

 June 25th. Schonfeld states that, in part of 

 April and May, it appeared to have several 

 centres of condensation, and Vogel, in the be- 

 ginning of June, detected a much greater re- 

 semblance to a star-cluster than to a nebula. 



Dr. Winnecke succeeded in finding and ob- 

 serving this comet again on the 4th of August, 

 at half-past 2 A. M., and states that it was then 

 much brighter and larger than when at the 

 same distance from the sun in the month of 

 May before its perihelion passage. He esti- 

 mated its interior brighter part at 7' in diame- 

 ter ; but it appeared to be surrounded by dif- 

 fused faint light of much greater extent. The 

 comet was in perihelion a little before noon on 

 the 30th of June. At the beginning of Sep- 

 tember, its distance from the sun was about 

 115 millions of miles, from the earth about 46 

 millions, nearly the same as it was in the mid- 

 dle of May. 



The Common Origin of Certain Comets. 

 Professor Daniel Kirkwood contributes to the 

 American Journal of Science for September, 

 1869, a paper on the remarkable resemblance 

 between the orbits of the comet of 1812, dis- 

 covered by Pons, and the fourth comet of 

 1846. The elements of the two comets are 

 wonderfully like, so much so that diagrams 

 describing their paths are almost exactly simU 

 lar to the eye. The author remarks that it is 

 infinitely improbable that these coincidences 

 should be accidental ; and that they point un- 

 doubtedly to a common origin of the two ob- 

 jects. These comets have their aphelions very 

 near the orbit of Neptune, and he argues that 

 the original parabolas in which they moved 

 were probably transformed into ellipses (the 

 present form) by the perturbations of that 



