Land Ice of Arctic and Sub-Arctic Regions 45 



peat, floating it in a state of semi-buoyancy above tbe frozen sub- 

 stratum of alluvium or peat so tbe ice may accumulate season after 

 season, as long as tbere is a growing and buoyant equilibrium main- 

 tained between tbe annually tbawed peaty superstratum and the 

 constantly frozen substratum. 



The condition of semi-buoyancy or flotation frequently exists in 

 bogs in temperate latitudes where the cold of winter is not sufficient 

 to freeze the water underneath the peat, or at least where the annual 

 result of such freezing they may be subjected to does not permit of 

 ice surviving from year to year in whole or in part as it does in 

 higher latitudes. 



The Solway Moss in Cumberland, England, is a familiar histori- 

 cal instance of a semi-buoyant bog without ice underneath. It is 

 of tradition that at the defeat of the Scots in this locality by the 

 English in 1542, a troop of horsemen heavily mounted and heavily 

 armored was put to rout. In the panic of their flight they ran 

 headlong into this peat bog and became engulfed. More than two 

 hundred years later, at the end of the eighteenth century, it is re- 

 corded that a digger of peat came upon a man and his horse sup- 

 posed to be one of this troop, for both were in complete armor and 

 preserved from total decay by the antiseptic qualities of the peat. 

 In 1 77 1 this bog, surcharged with the water of heavy rains, rose, 

 swelled, burst, and swept over houses and trees in its course. It 

 is easy to see how bogs similar to this might, if subjected to a cli- 

 mate as severe as that now prevailing in the Arctic regions, exist as 

 an icy mass.^^ 



The tundra mantle that covers practically all of this northern 

 region, with the conditions it imposes upon the drainage of the 

 country together with its properties as an insulating material are 

 important if not the chief factors in the formation and preservation 

 of ice. In considering its total and generalized effects there are 

 presented a variety of conditions and probabilities upon which there 

 is no data. Some of them are : the continuous summer heat and its 

 total thermal eft'ect, absorption, radiation, etc. The heat involved 

 in the growing of the cryptogams that make up the large bulk of 

 the tundra, and whether the effects are appreciable. Spontaneous 

 combustion of peat, chemical decomposition of vegetable matter 

 generating gases and heat and what effect these may produce in 

 floating bogs and the ice they protect from disintegration. 



*' See interesting notes about bogs in " Facts About Peat," T. H. Leavitt, 

 Boston, 1867. Third edition. 



