Astronomical Society. Gt 



very extensive series of experiments on tlie various forms of elec- 

 trical plienomena vhicli were produced by it, and more particularly 

 with reference to a comparison of its effects with those produced 

 by a powerful voltaic pile, which Mere undertaken at the express 

 request of Volta liimself. Dr. van Maruni Mas remarkable for liis 

 very various acquirements, and Avas the author of many memoirs in the 

 Haarlem and other Transactions, on botanical, chemical, phj'sical, and 

 other subjects : he was a man of the most simple habits and of the most 

 amiable character, and devoted himself most zealously during the 

 greatest part of a very long life to the cultivation of scieuce, and to 

 the pi'omotion of the interests of the establishment over which he 

 presided. 



Gentlemen, I have now arrived at the last and most painful part 

 of my duty in addressing you, which is most gratefully and most re- 

 spectfully to bid you farewell. 



ASTRONOMICAL SOCIETY. 



Nov. 9, 1838. — The following communications were read: — 



I. Astronomical Observations made at the Imperial Observatory 

 at Wilna, in the year 1885. By M. Slavinski. 



Tliese observations are of a similar nature to those made in former 

 years, and communicated to the Society from time to time. The 

 present collection consists of observations of Jupiter, Saturn, Mars, 

 and Uranus, as well as of moon-culminating stars, occultations of 

 stars by the moon, and eclipses of Jupiter's satellites. The geo- 

 centric right ascension and declination of each planet, and for each 

 day of observation, are compared with the positions deduced from 

 Encke's Berlin Ephemeris, and the differences noted. In the case 

 of Jupiter these differences in right ascension are all positive, and 

 the maximum difference is P,36 ; in declination the maximum dif- 

 ferences are — 4"-l and -f 6""9. In the case oi Saturn, the differ- 

 ences are likewise (with one slight exception) all positive, the maxi- 

 mum being 0^,80 ; the same remark applies to the declinations, the 

 whole of the differences lieing positive, and varying from I5"-6 to 

 28"* 1. In the case of Mars, the differences in right ascension vary 

 from — 0%25 to +0^52 ; and in declination from — 1"-9 to +17"-G. 

 In the case of Uranus, the differences in right ascension are very 

 considerable, and all positive, varying from 3^,07 to 4',02 ; but in 

 declination the differences are not so great, being confined within 

 — 4""9 and 4-3"'9. These large errors in the tables of some of the 

 planets are confirmed by observations made at other observatories ; 

 and will doubtless, in time, lead to their correction. 



The observations of the moon-culminating stars were made on 

 thirty-two days at various ])arts of the year, each ol)servation being 

 made with the five wires of the transit. Only six of these observa- 

 tions were made of the second liml) of the moon. 



The occultations are six in numl)er ; one being of Saturn on the 

 27th of August ; and the others of various stars. There are ten 

 eclijjses of Jupiter's satellites ; viz. five of the first, and five of the 

 second. To the whole is subjoined the monthly mean of the baro- 



F2 



