420 TRANSIT OF VENUS, 1874. KERGUELEN ISLAND. 



For the difference of longitude between Molloy Point and Observatory Bay 

 we have the following : 



Molloy Point, 



East of 

 Observatory Bay. 



in 8 



By chronometers in the Gazelle o. 47 4 (Auwers). 



By chronometers in the Volagc o. 46 9 -> 



Again by chronometers in the Volage . o. 46 3 > See next section. 



By rocket signals o. 47 2 J 



Mean o. 46 g5 



The same occultation was also observed at the German Station at Betsy 

 Cove, Kerguelen's Island. Professor A. Auwers kindly communicates the 

 following, by letter dated 1879, October 18 : 



" From the occultation of 9 Tauri, 1874, December 20 (good observations, 

 two observers) 



" Longitude of Betsy Cove, East of Greenwich, 4 h . 40 m . 43 St 2 ; 

 with mean error, 2 s- 6. 



" I have computed this occultation with Newcomb's corrections to 

 Hansen's Tables, modified so as to agree with the Luxor occultations.* The 

 mean error has been found, supposing the mean error of each relative 

 co-ordinate to be 1"'5." 



The last occultations observed at Luxor were on 1874, December 15, only 

 five days before the Kerguelen occultation; and, the longitude of Luxor 

 having been obtained by telegraphic signals with Mokattam, it may be 

 supposed that Dr. Auwers' reduction of the occultations is the most free 

 from systematic errors. 



The difference of longitude between Betsy Cove and Observatory Bay was 

 found as follows : 



Betsy Cove, 



East of 

 Observatory Bay. 



* Beobachtung des Venus-Durchgangs von 8 December 1874, in Luxor, von A. Auwers. 

 Berlin, 1878, page 122. 



