478 TRANSIT OF VENUS, 1874. KERGUELEN ISLAND. THUMB PEAK. 



It will be remarked that the record of times in the last column does not in 

 any way depend on the longitude of Thumb Peak, being directly referred to 

 the Transit-Clock at Observatory Bay. The absolute times of the phenomena 

 depend in a very slight degree on the geographical co-ordinates of Thumb 

 Peak. 



The corrections to the Transit-Clock (below) are interpolated from those in 

 Part IV., Section 1, Tables IV. and V. 



The Greenwich Sidereal Times, which are required for interpolation of 

 tabular places of Sun and Venus, are formed by subtracting from the Obser- 

 vatory Bay Sidereal Times the value, 4 h . 39 m . 33 8 '5, of the eastern longitude 

 of Observatory Bay, 



The Thumb Peak Sidereal Time, which is required for computing the 

 factor of parallax, is formed by adding l m . 7 9 '7, the longitude of Thumb 

 Peak East of Observatory Bay, to the Observatory Bay Sidereal Time. 



