THE CONQUEST OF THE ZONES 



plest calculation what particular region lies directly 

 beneath the sun at any given time. If, for example, 

 his chronometer shows jQve o'clock Greenwich time, he 

 knows that the sun's position, as observed at the mo- 

 ment, marks the meridian five hours (i.e., 75° of longi- 

 tude) west of Greenwich. 



While the arctic region appears thus to have given 

 up its last secret, this is not as yet true of the antarctic. 

 The expedition of Lieutenant (now Sir Ernest) Shackle- 

 ton, in 1908, approached within about one hundred 

 and eleven miles of the South Pole. The intervening 

 space — less than two degrees in extent — represents, 

 therefore, the only stretch of latitude on the earth's 

 surface that has not been trodden by man's foot or 

 crossed by his ships. More than one expedition is 

 being planned to explore this last remaining strong- 

 hold, and in all probability not many years — perhaps 

 not many months — will elapse before the little stretch 

 of ice that separated Lieutenant Shackleton from the 

 South Pole will be crossed, and man's conquest of the 

 zones will be complete. 



[S5l 



