CHAP. XXIV. WIXTER PHENOMENA OF THE ST. LAWRENCE. 51 



The frosts commence about the end of November, and a 

 margin of ice of some strength soon forms along the shores of 

 the river, and around every island and projecting rock in it ; 

 and wherever there is still water it is immediately cased over. 

 The wind, acting on this glacial fringe, breaks off portions in 

 various parts, and these jDroceeding down the stream constitute 

 a moving border on the outside of the stationary one, which, as 

 the intensity of the cold increases, is continually augmented by 

 the adherence of the ice-sheets which have been coasting along 

 it ; and as the stationary border thus robs the moving one, this 

 still further outflanks the other, until in some part, the margins 

 from the opposite shores nearly meeting, the floating ice becomes 

 jammed up between them, and a night of severe frost forms a 

 bridge across the river. The first ice-bridge below Montreal is 

 usually formed at the entrance of the river into Lake St. Peter, 

 where the many channels into which the stream is split up 

 greatly assist the process. 



As soon as the winter barrier is thrown across (generally 

 towards Christmas), it of course rapidly increases by stopping 

 the progress of the downward floating ice, which has by this 

 time assumed a character of considerable grandeur, nearly the 

 whole surface of the stream being covered with it ; and the 

 quantity is so great, that, to account for the supply, many un- 

 satisfied with the supposition of a marginal origin have recourse 

 to the hypothesis that a very large portion is formed on and 

 derived from the bottom of the river, where rapid currents 

 exist. 



But, whatever its origin, it now moves in solid and extensive 

 fields, and wherever it meets with an obstacle in its course, the 

 momentum of the mass breaks up the striking part into huge 

 fragments that pile over one another ; or, if the obstacle be 

 stationary ice, the fragments are driven under it, and there 

 closely packed. Beneatli the constantly widening ice-barrier 

 mentioned, an enormous quantity is thus driven, particularly 

 when the barrier gains any position where the current is stronger 

 than usual. The augmented force with which the masses then 

 move, pushes and packs so much below, that the space left for 

 the river to flow in is greatly diminished, and the consequence 

 is a perceptible rise of the waters above, which, indeed, from the 



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