We may perhaps better understand the case by supposing a certain economic development to take place in England in the distant future. At present we remain, as we are likely long to remain, economically advantaged or beneficed for manufacture by our coalfields, which are unequalled in Europe, though Germany, through the invention which made her phosphoric iron workable, has a larger store of the chief industrial metal. In return for our coal and manufactures and our shipping services, we import foods and goods that otherwise we could not pay for; and the additional revenue from British investments in foreign debts and enterprises further swells the food and raw material import, thus depressing to a considerable extent _our_ agriculture under a system of large farms. When in the course of centuries the coalfields are exhausted, unless it should be found that the winds and tides can be made to yield electric power cheaply enough, our manufacturing population will probably dwindle. Either the United States will supersede us with their stores of coal, or--if, as may well be, their stores are already exhausted by a vaster exploitation--China may take the lead. The chief advantage left us would be the skill and efficiency of our industrial population--an important but incalculable factor.[205] A "return to the land," if not achieved beforehand, might in that case be assumed to be inevitable; but should Australian, Indian, and North and South American wheat-production continue (as it may or may not) to have the same relative advantages of soil, our remaining city populations would continue to buy foreign corn; and the land might still be largely turned to pasture. That remaining city population, roughly speaking, would in the terms of the case consist of (_a_) those persons drawing incomes from foreign investments; (_b_) those workmen, tradesmen, and professional people who could still be successfully employed in manufactures, or whom the interest-drawing classes employed to do their necessary home-work, as the Romans perforce employed to the last many workmen and doctors and scribes, slave or free; (_c_) those who might earn incomes by seafaring; and (_d_) the official class--necessarily reduced, like every other. Until the incomes from foreign investments had in some measure disappeared, the country could not gravitate down to an economically stable recommencement in agriculture.