8 



0. Backlund, 



In Betreff der Windsor-Bcobachtungen bemerkt Herr Tebbutt: 

 Owing to there being 110 îmcleus or other dcfinite condensation in the Cornet the obser- 

 vations were made with extreme difficulty. All I could do was to note as carefully as pos- 

 sible its bissection at the edges of the ring, the Comet varying from one to two minutes of 

 arc in diameter. Astr. Nachr. Bd. 94. 



Instrument: éy.zôlliger Refractor. Kreismikrometer. 



Die Beobachtungen in Melbourne sind ebenfalls an einem 4y 3 zölligen Refractor ange- 

 gestellt. Das vom Astronomer Royal Ellery übersandte Manuscript enthält folgende 

 Notizen: 



The observations of the 10 th and 14 ih were made with a wire micrometer, the wires of 

 which are thick enough to be visible in twiligth or moonligth. The second set of the 21 6t and 

 tliose of the 22 nd and 25 th were made with a screw micrometer furnished with flat bars in- 

 stead of wires, and sufficiently wide to be seen on any clear night. The other observations 

 were made with a rhombus formed of similar bars to those in the micrometer just mentio- 

 ned, of which the diagonals were as nearly as possible equal. On each occasion the comet 

 was of the last degree of faintness, and presented the appearance of a nebulous haze without 

 any condensation of ligth towards the centre, and of which the outline was rather irregulär. 



Erscheinung- 1881. 



Die Elemente, welche zur Vorausberechnung der letzten Erscheinung gedient haben 

 (Bulletin de l'Académie de St. Pétersbourg, T. XXVII № 4), waren nicht ganz genau, theils 

 weil die Accélération der mittleren Bewegung zu gross in Rechnung gebracht war, theils 

 auch in Folge eines kleinen Fehlers, welcher sich in die Berechnung der Saturnstörungen 

 eingeschlichen hatte; nach Anbringung vorläufiger Correctionen konnten sie indess zur Her- 

 leitung der Normalörter für diese Erscheinung angewandt werden. 



Elemente. 



Epoche und Oscillation 1881 Juli 2,0 M. B. Z. 



M 0 = 



319°23' 3"31 



? = 



57 4249,12 



я = 



334 34 4,22 J 



iz — 



158 30 8,59 \ M. Aequ. 1881,0 





12 53 0,91 j 



I х = 



1072"46904 



