Draw two lines on your map, the upper one running from the mouth of the St. Lawrence westward nearly to St. Paul on the Mississippi, and the lower one from the neighborhood of St. John's in Newfoundland running southwesterly about to the point where the Wisconsin joins the Mississippi, but jutting down to form an extensive peninsula comprising part of the States of Indiana and Illinois, and you include between them all of the United States which existed at the close of the Devonian period. The upper line rests against the granite hills dividing the Silurian and Devonian deposits of the British Possessions to the north from those of the United States to the south, Canada itself consisting, in great part, of the granite ridge. How far the early deposits extended to the north of the Laurentian Hills, as well as the outline of that portion of the continent in those times, remains still very problematical; but the investigations thus far undertaken in those regions would lead to the supposition that the same granite upheaval which raised Canada stretched northward in a broad, low ridge of land, widening in its upper part and extending to the neighborhood of Bathurst Inlet and King William's Island, while on either side of it to the east and west the Silurian and Devonian deposits extended far toward the present outlines of the continent. Indeed, our geological surveys, as well as the information otherwise obtained concerning the primitive condition of North America and the gradual accessions it has received in more recent periods, point to a very early circumscription of the area which, in the course of time, was to become the continent we now inhabit, with its modern features.[A] [Footnote A: It would be impossible to encumber the pages of the _Atlantic Monthly_ with references to all the authorities on which such geological results rest. They are drawn from the various State Surveys, including that of the mineral lands of Lake Superior, and other more general works on American geology.]