ft 



ASTRONOMY. PROGRESS OF, IN 1808. 



rfMMrrte* ttttr - ITMSSMBM. Since the last record names have been given 



!!::- !M! : 



Prot Ball in the 



so closely with thote of 

 1884 and 1887 a* 



1*1^ dtv^^Ml * At^MV 



iddle risw K from its 



, - I1C 111% I I* 



> ring fa, from its discoverer, called the 



IdiV&oa. TWorte* ring hs* occasionally 



teen MI to be divided also, and this separation 

 ha* basfi MMDed the JhnA division. 



ef ntsML-This. the largest of 

 fa the only one of his 8 

 led to successful 

 Dr. Barnard has 



ssneh time to this object, but it * 

 med that the atmosphere was sufficiently 

 fortttopc^tawNi-deflDeddisk.wuh- 

 of ooorse. no measures could be 

 the disk was observable a mag- 

 of 1 000 diameters was uf^d, and 



. . ' :,,.:, 



of the observations of the year 18M, on May 6 

 and 7. June 18 and 85. and July 2: Diameter, 

 This is a smaller di- 



thaa that aeuallj assigned to Titan, and 

 about 5-3 times M great as 

 Saturn's density being equal 

 pine wood. 



16. Inthe-Astronomi- 

 0. 18K). Dr. Barnard writes 

 of the diameter of this, the most distant known 

 planet, and of his employment upon it of the 36- 

 inch tiisSBOpi with, generally, a power of 520, 

 ihoagfe oo one or two occasions using a power 

 Save in a single case the 

 I round, while in the obser- 

 Tranu* the disk was ever decidedly 

 elUotlesa. Following are the results of the 

 work of Ua nights reduced to the mean distance 

 from the son =*HK51. in terms of the Earth's 

 = 1: 



Tne exact number of these small 



M 



819 



sa*- 



\i 



SM \\ r...rdlk. 



89* = lit 



401 = HI Ottilia. 



Over one hundred of these tiny planets are 

 MM .. , 



The planet BE has an interesting orbit, ami. 

 in contrast to nearly all the others, raav 

 of dome practical value to astronomers.* With 



. ; rfbb exception --f ::-,?:: . I'.nieim. Us j,, T i- 

 helioii distance is the smallest of the cut in- 

 family, being but 1*60. Its least distance from 



" M .(HX) mil. 



thai .f the Earth boi 03,000,000. It i> 

 therefore well adapted fur tin- drternuimtion f 

 the solar parallax, as whet i in opposition and <>n 

 the meridian at midnight. >>cin^ in the telescope 

 l-.jt a minute point, it is of far greater accuracy 

 f..r the jix-ertainineiit of the Sun's distance than 

 a transit of Venus. 



I neke'a Comet, with a period of only 8-3 

 years, was detected by M. Perrotin on N 

 1894, at the Nice Observatory, Prance. 'I 

 the most interesting of all the short-period 

 comets, not only because its time of revolution is 

 the shortest, but because of its near approach to 

 the planet Mercury, thus affording the most re- 

 liable data known for determining the mass of 

 that planet. In 1801 it came quite near the 

 planet, and gave opportunity for a long s< ; 

 observations, from which the most trust v. 

 value for Mercury's mass ever assigned was de- 

 duced. Its periodic time at each return is 

 found diminished by about two and a half hours, 

 which fact has caused much speculation and 

 wonder, and is yet an unsolved problem. The 

 theory regarding this retardation which has most 

 adherents is that it is caused by the resistance 

 of the hv|)othetical, all-pervading ether, and 

 this retardation of its motion shortens its periodic 

 tin..-. 



Comet IT 1894 was discovered on Nov. 20 

 by Edward D.Swift, assistant astronomer at the 

 Lowe Observatory, Echo Mountain, California. 

 It was detected with a 16-inch refractor, and, 

 having passed perihelion, was an exceedingly 

 j"t. A very faint, short tail was per- 

 . A computation of its orbit from three 

 positions showed it to be not only an elliptic com- 

 et of short period, but, also, that its elements 

 were almost identical with the lost comet of 

 o, discovered in 1844, with a computed 

 : of about five and a half years, which 

 had not again been seen until this finding by 

 Swift. Though possible, it is exceedingly im- 

 probable that two comets should possess nearly 

 the same elements, and astronomers are agreed 

 that this new comet is a return of De Vico's to 

 perihelion, which must have happened nine 

 times without detection. 



The observations and measurements of this 

 comet br Dr. Barnard, who followed it with the 

 great telescope until Jan. 29, 1895, were of great 

 value in computing a more exact set of elements. 



From all observations Dr. Chandler, of Cam- 

 Mon, Mass., has computed the following ellip- 

 tic elements, and for comparison the elements of 

 ^o's comet, by Brunow, are given : 



