54 



ASTRONOMY, PROGRESS OP, IN 1891. 



of November shower, it returns with unfailing 

 regularity and is prolonged for several days, 

 while all the others last but a few hours. The 

 first meteors were seen at its last return on Aug. 

 2, and they were observed in greater or less num- 

 bers on every morning until Aug. 12. A satis- 

 factory explanation of such a prolongation has 

 never been given. Its radiant is in Perseus, and, 

 instead of being a point, extends, according to 

 observations of the writer, continued through 

 several years, over an elliptical area whose axes 

 are about 10 by 5. No well-authenticated ac- 

 count of stone falls has been announced. 



Meteorites. A paper on this subject was read 

 at the recent meeting in Washington of the 

 American Association for the Advancement of 

 Science by Prof. A, E. Foot, of Philadelphia. 

 He says that in Crater Mountain, 185 miles north 

 of Tucson, Arizona, he found small meteoric 

 fragments scattered over an area a third of a 

 mile in length by 120 feet in width, extending 

 from northwest to southeast. Exactly in line 

 with it but outside the crater, about 2 miles dis- 

 tant, were two meteoric stones, weighing 154 and 

 201 pounds respectively, and 131 smaller frag- 

 ments ranging from one sixteenth of an ounce 

 to 6 pounds 10 ounces. A section of a mass of 

 40 pounds, of extreme hardness, was exhibited 

 at the meeting, " which revealed cavities con- 

 taining small, black objects, one fiftieth of an 

 inch in diameter, with which polished corundum 

 was cut as easily as a knife might cut gypsum," 

 and suggested the idea of diamonds. But the 

 published statement that all the geologists pres- 

 ent were agreed that they were diamonds is erro- 

 neous, and the writer has the assurance of one 

 of our most celebrated meteorologists, who exam- 

 ined them, that they certainly are not those gems. 



Comets. Since Oct. 6, 1890, the date of the 

 last discovery of a comet given in our last vol- 

 ume, the following comets have been discovered, 

 numbered in the order of their finding rather 

 than their perihelion passage : Comet e, by 

 Prof. Zona, of Palermo, Italy. These are the 

 computed parabolic elements : Perihelion pas- 

 sage = 1890, July 27-713, Berlin mean time ; from 

 node to perihelion = 328 53' ; longitude of node 

 = 86 28' ; inclination = 155 2' ; log. q. = 0-314. 



Comet / 1890 was detected by M. Spitaler 

 at Vienna on Nov. 16. At receipt of the news 

 in Vienna of the discovery of Zona's comet, the 

 day after its finding, Spitaler directed the 27- 

 inch refractor to the indicated place, and caw at 

 once a very faint object in the field, but, as it 

 was much fainter than the telegram asserted, he 

 sought farther, and found the Zona comet. Re- 

 turning to his first object, he saw that it had 

 moved, and that he had achieved a most extraor- 

 dinary and entirely unprecedented event in as- 

 tronomy viz., the having in almost the same 

 field of the telescope two comets moving in dif- 

 ferent directions. The following elliptic ele- 

 ments have been computed : Perihelion' passage, 

 1890, Oct. 26-60123, Berlin mean time ; longi- 

 tude of perihelion = 58 25' 58'2" ; longitude of 

 node = 45 5' 51-7" ; inclination = 12 50' 44-5" ; 

 log. of a = 0-537532 ; period = 6'4 years. 



The discoverer has reasons for supposing this 

 to be its first appearance in its present orbit, 

 which, he thinks, was changed into this form by 

 a near approach to Jupiter in the latter part of 



1887. Its aphelion distance is smaller than 

 Encke's, or less than that of any known comet. 



Comet a 1891 was discovered by Prof. E. E. 

 Barnard, at the Lick Observatory, on March 29, 

 and by W. P. Denning, of Bristol, England, on 

 the succeeding night. The annexed parabolic 

 elements have been calculated : Perihelion pas- 

 sage, 1891, April 27-55900, Berlin mean time; 

 node to perihelion = 178 48' 24-8"; longitude 

 of node = 193 55' 36-5" ; inclination = 120 31' 

 27" ; log. perihelion distance = 9-599332. 



Comet b 1801. This is a return of Wolf's pe- 

 riodic of 1884, and was detected on May 1 by 

 Spitaler, and on May 4 by Barnard. On Sept. 

 4 it passed nearly over the center of the Pleiades, 

 treating astronomers to a sight no human eye 

 had ever seen. 



Comet c 1891 is an apparition of Encke's 

 comet which has the shortest period of any 

 known = 3-3 years. It was first seen on Aug. 1 

 by Barnard. The principal interest attaching to 

 it is the progressive diminution of its periodic 

 time, evidencing, as many suppose, the retarding 

 effect of the hypothetical, all-pervading ether. 

 Astronomers are not agreed, however, as to the 

 correctness of this conclusion. 



Comet d 1891 was discovered, on Sept. 28, by 

 Barnard, in right ascension 20 11 53 m 45 s , declina- 

 tion south 1 23'. This is a return of Swift's 

 periodic comet, discovered in 1880, and adds 

 another to the rapidly increasing list of short- 

 period comets. Though it was previously found 

 by Tempel in 1869, its periodicity was not then 

 predicted or even suspected. Hence, conforming 

 to a rule adopted by astronomers in the case of 

 Winnecke's, Tattle's, and Biela's comets, all of 

 which had been detected previously by others, 

 this should be called Swift's comet, but it is 

 usually denominated Tempel-Swift. The follow- 

 ing elements, which differ but little from those 

 of 1869-'80, have been computed for it, but the 

 comet at discovery was nearly five degrees from 

 its calculated place : Time of perihelion passage, 

 Nov. 14*958, Paris mean time; longitude of peri- 

 helion =43 14' 15-7"; longitude of node = 296 

 31' 14-8" ; inclination = 5 23' 13-8" ; logarithm 

 of perihelion distance = 0-036071. Motion direct. 



Comet e 1891 by Barnard, on Oct. 2, in right 

 ascension 7 h 31 m 24% declination south 27 54'. 

 From observations made at the Lick Observatory 

 on Oct. 3, 4, and 5, Prof. Campbell has computed 

 the following elements : Perihelion passage, Nov. 

 8*75, Greenwich mean time ; from node to peri- 

 helion = 262 6' ; longitude of node = 215 38' ; 

 inclination = 75 50' ; perihelion distance = 

 1-0166. It had a rapid motion southeast, and 

 was soon lost to northern observatories. 



Catalogues. The Astronomische Nachrich- 

 ten, No. 3,047, has published a list of 70 new 

 double stars discovered in 1890 by S. W. Burn- 

 ham, of the Lick Observatory staff, with the 36- 

 inch telescope. It is the seventeenth catalogue 

 of double stars published by him. From their 

 closeness they are very difficult objects, and re- 

 quire the largest telescopes for their examination. 

 Thirty-nine have distances less than 1-0", while 

 the average distance of all is 0-45". Twenty-five 

 are at a distance of 0-33". They cover a wide 

 range of magnitudes, the following being naked- 

 eye stars : B. A. C., No. 230, 199 Ceti, 95 Pis- 

 cium, Chi Persei, 48 Cephei (H), 34 Persei, B. A. 



