467 



CHRONOMETRIC CONNECTIONS OF THE STATIONS IN KERGUELEN ISLAND, 



ROYAL SOUND. 



The list of the chronometers supplied to Lieut. Corbet has been already 

 given. On December 15, all of them being lodged on board the Volage, 

 Lieut. Corbet commenced operations. 



His method of proceeding was to compare the Sidereal Chronometer Z 

 with all the others by coincidence of beats ; I, m, n were then taken on shore, 

 compared with the transit-clock of the station, carried back to the ship, and 

 again compared with Z. 



The Volage made the following trips : 



December 17 d . 19 h . left Observatory Bay ; called at Molloy Point (American 

 Station) 21 h . 30 m ., at Thumb Peak December 18 d . P., and at Supply Bay 

 December 18 d . 5 h . 39 m . ; returned to Observatory Bay December 18 d . 10 h . 



December 20". 17 h . left Observatory Bay ; arrived at Thumb Peak 20*. 21 1 '., 

 Molloy Point 21 rt . 2 h . ; returned to Observatory Bay at 6 h . 30'". 



December 21 d . 17 h . left Observatory Bay ; arrived at Supply Bay 21 d . 21 h . ; 

 and returned to Observatory Bay 23 (1 . 8 h . 



December 29 left Observatory Bay 17 h . 30 m . ; arrived at Betsy Cove 

 (German Station) December 30 d . 5 h . ; left Betsy Cove 17 h . ; returned to 

 Observatory Bay December 31A 4 h . 



Lieut. Corbet himself reduced the comparisons in the following manner : 

 From the double comparisons of /, m, n with Z, and the comparisons of the 

 same three chronometers with the transit-clock of a station, the error of Z 

 on local sidereal time was found, assuming an error of the transit-clock. 

 The remaining chronometers A to H were treated as sidereal chronometers 

 with large losing rates, and their errors on local sidereal time inferred from 

 the comparisons with Z. The rates of the chronometers were inferred from 

 the comparisons at Observatory Bay, and the deduced longitudes of the 

 various stations were referred to Observatory Bay. 



I examined Lieut. Corbet's work and found it to be correct. It was there- 

 fore only necessary to apply to his results the corrections due to the difference 

 between the clock-errors used by him and the clock-errors finally adopted- 

 For Molloy Point these were kindly supplied by Professor Newton, and for 

 Betsy Cove by Dr. Auwers. 



[The mass of comparisons of the chronometers A to H with Z is very great. 

 I have not thought it necessary to print them. G. B. A.] 



