22 ASTRONOMICAL OBSERVATIONS 



The weighted mean from nine observations is 4'' 43™ 34' jf 13\ If we combine 

 the results according to tlie moon's limb, we find: — 



From observations of <I I i^ 43m 14s v^reio-ht 8.5 



c: n 4 43 50 " 10.5 



Mean 4 43 32 



which last value I have adopted. 



Record and Reduction of the Occultations and Eclipse, observed at Van 

 Rensselaer Harbor. 



The observations of occultations and of an eclipse were made at the Winter 

 Quarters in latitude 78° 37' 04", and in approximate west longitude 4'' 43°" 32^ 



In the following record, the times are given by chronometer, uncorrected for 

 error and rate, in the two accounts of it in Appendix No. IX., second volume of the 

 Narrative, pages 398 and 399, and in No. 1017 of the Astronomische Nachrichten, 

 pages 135 and 136, the time is mean local time, as made out by Mr. Sonntag. 



Occultation of Saturn. December 12, 1853. 



Immersiou at 1^ 03'" IP.G Pocket chronometer. A. Sonntag, observer. 



7 28 49.0 Chronometer No. 2143. Dr. Hayes, 

 1" before the complete disappearance. 

 Emersion at 7 36 50 Pocket chronometer. A. Sonntag, observer. 



Perhaps 10' too late. 



JVbfe.— Moon's limb much undulating. The telescopes were one of English make and one by Fraun- 

 liofer, each of thirty-inch focal length. At immersion the time was noted when the last point of Saturn's 

 ring disappeared behiud the moon's limb ; at the emersion, the time is given when the last point of the 



ring parted from the moon's limb. Chronometer comparisons : 



Pocket chronometer G'' 21™ 19^3 No. 2143 6'' 47™ 1 



22 36.0 " 370 40 ,,, ^. , 



Qj q i f) „ Q^g, in > All mean tnne chronometers. 



26 30.7 " 264 29 J 



Occultation of Saturn. January 8, 1854. 



Immersion at lO'' 10" 30' Pocket chronometer. A. Sonntag, ol)server. 



Doubtful, perliaps obscured by a cloud. 

 Emersion at 11 07 06.5 Pocket chronometer. A. Sonntag, observer. 



Moment when the last point of Saturn's ring parted from the moon's limb. 

 For points of contact see note to the occultation of the 12th of December. Chronometer comparison 

 Pocket chronometer lO'' 18™ 30'. No. 2143 10'' 45'" 



Occultation of Saturn. February (4) 5, 1854. 



Pocket chronometer. A. Sonntag, observer. 

 No. 2143. Dr. Kane, 



Disappearance of last point of ring. 

 Pocket chronometer. A. Sonntag, observer. 

 Saturn's centre, 

 at 5 51 13.0 No. 2143. Dr. Kane, observer. 



Last contact of ring. The moon's limb was much undulatinfi:. 



