54 THE LABEADOE PENINSULA. cuap. xxiv. 



several days, and occasionally but a few hours, will intervene be- 

 tween them ; and it is fortunate that there is a criterion by which 

 the inhabitants are made aware when the ice may be considered 

 at rest for the season, and when it has therefore become safe 

 for them to cut tlieir winter roads across its rough and pinnacled 

 surface. This is never the case until a longitudinal opening of 

 some considerable extent appears in some part of St. Mary's cur- 

 rent. It has embarrassed many to give a satisfactory reason 

 why this rule, derived from the experience of the peasantry, 

 should be depended on. But the explanation is extremely 

 simple. The opening is merely an indication that a free sub- 

 glacial passage has been made for itself by the water, through 

 the continued influence of erosion and temperature, the effect 

 of which, where the current is strongest, has been sufficient to 

 wear through to the surface. The formation of this passage 

 shows the cessation of a supply of submerged ice, and a conse- 

 quent security against any further rise of the river to loosen its 

 covering for any further movement. The opening is thus a 

 true mark of safety. It lasts the whole winter, nev^er freezing 

 over, even when the temperature of the air reaches 30° below 

 zero of Fahrenheit ; and from its first appearance, the waters of 

 the inundation gradually subside, escaping through the channel 

 of which it is the index. The waters seldom or never, however, 

 fall so low as to attain their summer level ; but the subsidence 

 is sufficiently great to demonstrate clearly the prodigious extent 

 to which the ice has been packed, and to show that over great 

 occasional areas it has reached to the very bottom of the river. 

 For it will immediately occur to everyone, that when the mass 

 rests on the bottom, its height will not be diminished by the 

 subsidence of the water, and that, as this proceeds, the ice, ac- 

 cording to the thickness which it has in various parts attained, 

 will present various elevations after it has found a resting-place 

 beneath, until just so much is left supported by the stream as 

 is sufficient to permit its free escape. When the subsidence 

 has obtained its maximum, the trough of the St. Lawrence, 

 therefore, exhibits a glacial landscape, undulating into hills and 

 valleys that run in various directions ; and while some of the 

 principal mounds stand upon a base of 500 yards in length by 

 a hundred or two in breadth, they present a height of ten to 



