92 



POLAR PROBi^EMS 



central mass: fast-ice, pack ice, and the Arctic Pack (Fig. i). This 

 is the state of the ice cover during the greater part of the year, nine 

 to ten months at least. In summer, however, the fast-ice as such dis- 



FiG. 2 — Actual survey of an area in the outskirts of the Arctic Pack north of 

 Spitsbergen (80° 44' N. and 9° s' E.) on August 19, 1899, by Admiral Makarov showing 

 the ratio of ice cover to open water (here amounting to ioo:iS). Scale, 1:13,000. 

 (From p. 390 of work cited in footnote 5.) 



appears and passes over into the pack ice. Partly it is destroyed as 

 a result of breaking up and melting, partly it forms man^'-years-old 

 constituents of the pack ice. For two to three months of the year, 

 therefore, the ice cover of the Arctic Sea consists, properly speaking, 

 of pack ice and the Arctic Pack. 



Area Occupied by Each Class 



The main mass of ice that fills the central and largest part of the 

 Arctic Sea constitutes the Arctic Pack. It occupies about 70 per cent 



