182 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



tables or plates, varying from five to ten and twelve feet in 

 thickness, and from a few square yards to many acres in ex- 

 tent, which are formed by the breaking-up of the coast and 

 bay-ice in the month of June. These sheets, when pressed 

 to the coast by winds and urged by the unfailing arctic cur- 

 rent from the northwest, rise over the low-lying shores and 

 islands, removing every obstacle in their way, grinding and 

 polishing the surface, and rounding into boulders the masses 

 broken or torn from the cleavable rocks in their course. This 

 process, with some interruption from winds,' goes on for a 

 month or six weeks every year, and the bottom of the sea, to 

 the depth of twelve feet or more, exhibits white smooth sur- 

 faces, which have been thus ground and planed by the action. 



Pan-ice, according to this observer, is now "exerting an 

 abrading action over a vast, coastal and submarine area 

 throughout the shallow seas that fringe Labrador. In a word, 

 it is doing before our eyes, over a coast-line many hundred 

 miles in length, what has been done in earlier times over 

 a vast area of the North American continent, according as 

 fresh surfaces, by a rise or subsidence of the land, were 

 brought under the influence of pan-ice aided by an arctic 

 current. The evidence of a gradual uplifting of this coast 

 during the continuation of this process is seen in the smooth 

 worn surfaces up to more than COO feet above the present 

 sea-level. The material pushed to and fro along a shallow 

 sea-bottom by this action of ice must accumulate in subma- 

 rine depressions in the form of boulder-clay, which, however, 

 in a rising area, would, except where locally protected in 

 deep valleys, be remodelled by the action of the waves." To 

 such an action he attributes the boulder-clays of Nova Scotia. 



Similar views of the action of shore-ice are urged by J. 

 Milne, who, from his studies in Newfoundland and Labrador, 

 as well as in Finland, concludes that many of the phenomena 

 which some have referred to the action of an ice-cap, or a 

 great extension of land-ice, are due to the action of coast-ice 

 on an oscillating and especially on a rising submarine area. 

 On the other hand, the phenomena described on the shores 

 of Lake Ontario are strongly urged, by its advocates, in favor 

 of the hypothesis of subaerial glaciation. 



