The winter generally continues till the latter end of April, and sometimes even till May, when a thaw comes on very suddenly. The snow soon disappears; but it is a long time before the immense bodies of ice in the rivers are dissolved. The scene which presents itself on the St. Lawrence at this season is most tremendous. The ice first begins to crack from side to side, with a report as loud as that of a cannon. Afterwards, as the waters become swollen by the melting of the snow, it is broken into pieces, and hurried down the stream with prodigious impetuosity; but its course is often interrupted by the islands and shallow places in the river; one large piece is perhaps first stopped, other pieces come drifting upon that, and at length prodigious heaps are accumulated, in some places rising several yards above the level of the water. Sometimes these mounds of ice are driven from the islands or rocks, upon which they have accumulated, by the wind, and are floated down to the sea in one entire body: if in going down they happen to strike against any of the rocks along the shore, the crash is horrible: at other times they remain in the same spot where they were first formed, and continue to obstruct the navigation of the river for weeks after every appearance of frost is banished on shore; so very widely also do they frequently extend in particular parts of the river, and so solid are they at the same time, that in crossing from shore to shore, the people, instead of being at the trouble of going round them, make directly for the ice, disembark upon it, drag their bateaux or canoes across, and launch them again on the opposite side. As long as the ice remains in the St. Lawrence, no ships attempt to pass up or down; for one of these large bodies of ice is equally dangerous with a rock. [Sidenote: THAW.]