For a given country the problem is complicated by exchange. The exchange values, however, must be won on the home ground. England has, for example, a far greater population than she can feed, but her coal and iron have enabled her to manufacture and to carry for other nations. But England is now to a considerable extent using foreign supplies of the ores of iron. For a period she may do this and maintain her industry, through inertia, but imported raw materials and fuel could not permanently afford a basis for British industry, and for the present population of the United Kingdom. In that future, whenever it may come, the islands will contain the people whom they can feed, clothe and shelter, and no more.
Total resources, therefore, rather than total food production, determine how many people a given country can support, but in the world aspect total food marks an absolute limit, since we can not bring in food from Mars, even if Mr. Percival Lowell should convince us that she had a surplus.
It would be interesting to consider the United States in the light of the principles that have been suggested, but the story would be too long. We might simplify it by adopting the interesting and pleasant belief that our extraordinary range of resources would enable us to get on with little exchange, but this, as we have seen, would hardly change the result as to population. Mr. 0. P. Austin supports our hopes of three hundred million people by the comfortable assurance that we can grow all our sugar, all our rice, wine, tea, silk fibers, tobacco and most tropical fruits. Probably we could get on without diamonds and there are those who think our civilization might survive without coffee. But it would really make little difference whether we raised coffee or bought it with the proceeds of wheat. Or we might, indifferently, raise our silk, or sell farm machinery and buy silk, since either sort of production at present requires trees, and trees require land.
We have ventured the belief that we are sure of power. We may further include hopefully the resources of the underworld of the rocks, considering new reductions and uses of metals and many mineral substances. When the use of wood has come down to the minimum, the chief remaining demands on the soil, may, after all, be for food and clothing.
If we further suppose war and heavy armaments eliminated and all government honestly and economically administered, we shall cover a vast present waste. Thus to arrive at maximum population we must somewhat approach millennial conditions. Then, in high degree a self-sufficient nation, we could keep as many people as our own soil could feed and clothe. With wise timidity we have been deferring those large transactions in figures which the reader has been expecting, and we might with good show of reason, confess that inquiry for precise results is absurd and drop the attempt to forecast. Nevertheless, the next patriotic speech will marshal before us our future hundreds of millions,
