VENUS ON THE SUN'S FACE. 63 



liminary difficulties are overcome, we can hope more 

 from its indications than from those of any other 

 transit which will happen in the course of the next few 

 centuries. 



The transit will begin earliest for observers in the 

 neighbourhood of the Sandwich Islands, latest for 

 observers near Crozet Island, far to the south-east of 

 the Cape of Good Hope. It ends earliest for ob- 

 servers far to the south-west of Cape Horn, latest for 

 observers in the north-eastern part of European Russia. 

 Thus we see that, so far as the application of our 

 second method is concerned, the suitable spots are not 

 situated in the most inviting regions of the earth's 

 surface. As the transit happens on December 8, 1874, 

 the principal northern stations will be very bleak 

 abodes for the observers. The southern stations are 

 in yet more dreary regions, notwithstanding the fact 

 that the transit occurs during the summer of the 

 southern hemisphere. 



For the application of Halley's method we require 

 stations where the whole transit will be visible ; and as 

 the days are very short at the northern stations in 

 December, it is as respects these that we encounter 

 most difficulty. However, it has been found that 

 many places in Northern China, Japan, Eastern Siberia, 

 and Manchouria are suitable for the purpose. The 

 best southern stations for this method lie unfortunately 

 on the unexplored Antarctic continent and the islands 

 adjacent to it ; but Crozet Island, Kerguelen Land, and 

 some other places more easy of access than the Antarctic 



