358 ANNUAL REPORT SMITHSONIAN INSTITUTION, 192 8 



Facts so far available point to a rotary surface movement with 

 overflows from an overcharged Arctic basin, by the Greenland Sea 

 and other less important outlets. This movement may account for 

 the tendency of ice-bound vessels in the Arctic basin to take a periph- 

 eral drift, as the Frani^ Jeannette^ Karluk^ and Maud. It may also 

 explain the relatively smooth and unrafted ice reported from the 

 vicinity of the Pole. Again, the heavy ice to the north of Green- 

 land, which proved so baffling to the Nares expedition that it re- 

 ceived the title of paleocrystic ice, may be due simply to the heaping 

 and rafting against the land of the pack that has been swept past 

 the overflow of the East Greenland current. It can not, however, 

 be said that this circulation is proved. Many more observations are 

 required. 



Fluctuations in the amount of ice in the overflow currents may 

 well be due to variations in the strength of these currents. These 

 variations may be associated with departures from the normal in the 

 amount of water poured into the Arctic basin from the great Siberian 

 and American rivers, which in its turn depends on causes far re- 

 moved from Arctic regions. The complexity of the problem is almost 

 baffling, but even before the chain of cause and effect is traced useful 

 work could be done in looking for correlations. 



METHODS OF EXPLORATION 



Every age has seen a change in the methods employed in polar 

 exploration, and it may be of interest to review the resources of the 

 explorer in the light of modern knowledge. In the early days of 

 Arctic exploration attempts concentrated on the hope of finding an 

 open sea route to the north. Hence the lines of attack were by the 

 two gulfs of warmth due to the northward-flowing waters of the 

 North Atlantic drift, Hudson Bay with Davis Strait, and, particu- 

 larly, the Greenland Sea. By the early part of the nineteenth century 

 the hopelessness of advance by that means was realized, and not 

 long after the prospect of an open-water route across polar regions 

 in a lower latitude faded. Then came the period of probing the un- 

 known north from a land base in a high latitude from which sledge 

 journeys could take their start. Eventually the North Pole was 

 achieved by this means, long after Nansen, throwing aside all ac- 

 cepted canons of polar travel, had found a new and daring method. 

 Instead of avoiding besetment he courted it; instead of battling with 

 the floes he made use of their drift. 



Meantime, the age of steel prompted a new method of attacking 

 ice. The ice breaker was tried away back in 1899, when the Yermack 

 made an experimental voyage to the northwest of Spitsbergen. On 

 more serious exploration the Russians used ice breakers on the 



