On the Geology of the Island of Montreal. 199 



on the east by the St. Lawrence under its own proper name, 

 moving with a steady current between regular banks, two and 

 three miles apart, and sprinkled here and there with grassy 

 isles, of which the Boucherville group is the most numerous. 



This island, in shape, resembles an isosceles triangle. It is 

 thirty-two miles long in a northeast direction, and ten miles 

 in its greatest breadth, from the apex to the base. With the 

 exception of Montreal Hill, its subordinate alluvial ridge, and 

 one or two others of no great elevation, it exhibits a level sur- 

 face, watered by several rivulets, but none of note. It pos- 

 sesses a plentiful and well-tempered soil, vegetable and loamy; 

 but in the centre of the island there are occasional patches of 

 ferruginous sand ; and near Lachine, the ground is much in- 

 cumbered with bowlders. At St. Anne's, in the west, and 

 along the Riviere des Prairies, the rocks are sometimes thinly 

 clad, and show themselves in small platforms. The island is 

 traversed longitudinally by five roads, at regular distances 

 from each other, and with cross-cuts : another skirts its cir- 

 cumference. The relative situation of its villages will be best 

 learned by recourse to the accompanying map. PI. XV. 



Montreal Hill, overlooking on the southeast the rugged 

 Isle of St. Helen and the town to which it gives name, is 

 placed on the south side of the island, fourteen miles from its 

 lower end, and about a mile from the St. Lawrence. It stands 

 alone, in an extensive and highly cultivated plain, intersected 

 by large bodies of water, and terminated on the north and 

 south by mountains of fine features, but in other directions 

 stretching unobstructed into Upper Canada, and into the 

 eastern townships of Lower Canada. The aspect of this hill 

 is rendered striking by its massiveness, as well as by its posi- 

 tion. It dips on the east and southeast precipitously from a 

 rounded summit of scantily wooded rock, and elsewhere pre- 

 sents rugged hummocks, or steep declivities, clothed with 

 birch, poplar, and maple. Its base, and part of its sides, are 

 occupied by orchards, farms, and gentlemen's seats : excepting 



