“What a field for explorers is that Laurentian plateau! It is not possible for the most pessimistic person to fear that Nature has, by a strange coincidence, concentrated all the mineral wealth in the only part that is populated—that southern fringe which, though still only imperfectly prospected, has yielded over four hundred million tons of iron ore, nearly five thousand million pounds of copper, and immense quantities of silver and the other minerals I have mentioned. The explorations of the geological survey have shown that, scattered over the whole area, are patches of all the various formations that go to make up the pre-Cambrian; while practically every mineral that occurs in the south has been noted by explorers in the north. It is therefore quite safe to assume that, in the great northern areas as yet unattacked by the pick of the prospector, are vast stores of minerals that will come to light when the country is opened up.” I told Mr. Brock that, although he had dealt with only three of the geological provinces shared by Canada with the States, he had said enough to convince me that the Dominion possessed adequate mineral wealth to support its high destiny. “Still,” said Mr. Brock, “there is more to be told; and this very imperfect survey of our mineral resources must not be broken off in the middle. I now come to the fourth geological province, which it is convenient to name the Interior Plain. It embraces Alberta and the bulk of Manitoba and Saskatchewan, extending across the border into the Dakotas. It is pre-eminently an agricultural country, and is notably deficient in metallic minerals, as might be expected, because it is underlain with a thick blanket of almost undisturbed cretaceous and tertiary sediment. Gold dredging is carried on in the sands and gravels of the North Saskatchewan River below Edmonton; gypsum is mined in Manitoba; salt occurs in that province and in the lower Athabasca region; but with those exceptions, and materials used in the building trades, the mineral production of the Interior Plain is almost entirely confined to fuels, which, however, are very important. Natural gas over a wide area and under great pressure has been tapped, and there is every indication of a large oil field in, at any rate, the northern portion of Alberta, while some oil has been encountered in the south-west. The lower cretaceous sandstones along the Athabasca River, where they come to the surface, are for miles saturated with bitumen. These tar sands will probably average twelve per cent. in maltha, or asphaltum. Mr. R. G. McConnell saw tar sands occupying about one thousand square miles, which, taking the thickness at his estimate of 150 feet, would represent nearly five thousand million tons of bitumen. The lignites of the eastern plains are useful for local purposes, and beds more highly bitumenised are met with as the mountains are approached. Mr. D. B. Dowling has satisfied himself that there are 7,500 square miles of coal