230 THE CANADIAN NATURALIST. [Vol. Vlii. 



Islands to which it is keyed. When the pans are pressed on 

 the coast by winds, they accommodate themselves to all the 

 sinuosities of the shore line, and being pushed by the unfailing 

 arctic current, which brings down a constant supply of floe ice, 

 the pans rise over all the low lying parts of the Islands grinding 

 and polishing exposed shores, and rasping those that are steep- to. 

 The pans are shoved over the flat surfaces of the Islands 

 and remove with irresistible force every obstacle which opposes 

 their thrust, for the attacks are constantly renewed by the 

 ceaseless ice stream from the north-west, and this goes on unin- 

 terruptedly for a month or more. Sometimes a change in the 

 wind brings the endless sheet back again, and it is the middle 

 of July before some of the Fiords are clear of ice. Hence bould- 

 ers, shingle and beaches are rarely seen except in sheltered nooks 

 and coves, and the masses pushed or torn from those surfaces 

 where cleavage offers a chance of disruption, are urged into the 

 sea and rounded into boulder form by the raspiag and polish- 

 ing pans. 



Here too goes on the process, subsequently referred to, of 

 manufacturing Boulder Clay, for the deep hollows and ravines, 

 at present under the sea — the records of former glacial work — 

 are being filled with clay, sand, unworn and worn rock frag- 

 ments, producing a counterpart of some varieties of Boulder 

 Clay. 



But this is not all of the work of pan ice. The bottom of the 

 sea, to the depth of 12 or 15 feet, and at all less depths, is 

 smoothed and planed by the drifting masses when they pile ooe 

 on the other, and at depths, less than eight feet when the pans 

 are driven before the wind or carried by the currents. In sail- 

 ing from Aillik to Nain or to Cape Mugford, the fishermen send 

 a man aloft to look out for lt White Bocks." These are promi- 

 nences or swells in the general level of the sea bottom among the 

 Islands, from which every particle of sea weed has been removed 

 by pan ice. 



The " White Bocks" are clearly visible in smooth water, 

 and in rough weather "they break." Hence it is that pan ice 

 is exerting an abradiug action over a vast coastal and submarine 

 area throughout the shallow seas which fringe the Labrador. It 

 is pushing too the blocks of strata removed from the coast, back- 

 wards and forwards on the sea bottom, sometimes landing and 

 leaving them on islands, and again in the following season push- 



