The population beyond 1950 depends entirely upon the position we are to occupy in the future world nation, and, of course, no one knows what that is to be. If we are to sink into the position of a feeder for the densely packed rich and brainy masses in Northwestern Europe, then our population cannot be very great, but if we are to become a manufacturing nation ourselves, with world markets, the limit is merely that of the available food, and that is not enormous. The mistake was always made of overestimating our growth, and there is good reason to suspect that even the above conservative estimates are excessive. It is difficult to see how our high-priced labor will permit us to make things cheaply enough to compete with Europe, and even if we did compete successfully, it is not quite clear that the agricultural advances of forty years will produce food for 55,-000,000 people more than at present, when 10,000,000 are on the verge of want, if not actually underfed. Our population in 2,000 a.d. may be far less than 175,000,000, but having in mind the errors of Malthus who could not conceive of the present supersaturated masses of England, we are not safe in denying the possibility of even the 400,000,000 which some enthusiasts predict for the next century or two. Our density is now twenty-eight per square mile, but 400,000,000 would make it about 133 per mile, which would cast into the shade the conditions found in India, apparently an impossibility without food importations, and yet it is not at all impossible for Siberia, for instance, to supply the food, if Germans and Englishmen did not outbid us, as they seem destined to do.
The 2,000,000,000 of population, predicted by Professor Pritchetl* would be nearly one man for every acre of ground, including mountains and deserts. We support fifteen people for every eighty acres of cultivated farm land. Less than half our land is in farms, and less than one-fourth is improved, but even if two-thirds could be made productive, 400,000,000 of people would require us to support twenty-five from every eighty acres. Likewise, the time when our farms are to be divided up is very far off. Less than half our population is rural, and if the average farm is to be one-half the present average we will no doubt accommodate 40,000,000 this way. Eastern farmers generally agree that the best-paying farms are not larger than eighty acres, but this size is far off, because our average farm which, in 1850, was 202 acres (thirty-eight per cent, improved land), had only come down to 146 acres in 1900 (fifty per cent, improved). Such utilization of land now unproductive is a matter of centuries, on account of the expense of reclaiming swamps and constructing irrigating works, and even then we may have to leave immense areas in forests.
* Popular Science Monthly, 1901.
It is known that in prehistory Europe was one vast forest which gradually melted away as man increased in numbers. Two thousand years ago Gaul was still half forest, and Germany probably more than half. A thousand years ago, nearly all the mountains were still covered with trees. The process of deforestation still goes on, for if more food can be obtained from the land, the trees must perish. That is, although primitive man was a forest dweller absolutely dependent upon the woods, modern man gets his living elsewhere, and communities of men are antagonistic to communities of trees. Yet the antagonism is not complete - there is still a mutual aid, for if deforestration is carried too far, productiveness is diminished and man melts away. Barren areas now devoid of population, were once teeming with men. The soil made by forests was very fertile, but when deforestrated it had no protection and in time was washed away. For the preservation of water supply, wood supply and prevention of disastrous floods and landslides, it is necessary to keep a certain amount of land well forested. Perhaps that will always be a necessity, though, of course, there may be ways found in future ages of substituting some smaller and more productive plants for trees. But in the meantime for the highest density of population a certain percentage of forest is needed, and the time when an enormous population can live where present forests exist is very far off.
It does seem that the time is not so far off when our population must increase very slowly, if at all. There is a possibility of decreases from even the present numbers, for we are so rapidly using up the resources which support the factory population. This is the reason for that tremendous movement now under way to conserve our natural wealth. At the increasing rates of consumption it has been predicted that our timber will be exhausted in twenty years, and our gas, petroleum and anthracite in fifty. The copper mines must be exhausted in time, and the end of the iron ore is already in sight, for it is not inexhaustible, as we once thought. As so graphically described by a recent writer, Pittsburgh may go the way of Tyre and Sidon, which died of prodigality in using up their resources. There is an enormous waste, but even if we save this the end is only postponed. Similarly, we waste enormous amounts of food, but if we saved and utilized it, the proportionate increase of population would be very small.
Soft coal will also go eventually, but that may not be such a disaster, for by that time the utilization of water power may have progressed sufficiently to give all the light, heat and power needed by an enormous population essentially agricultural. Of course, the high prices due to diminishing supply will check consumption, and the end will be further off than present rates indicate, but that, too, necessitates a reduction of population. We are now like a spendthrift, using his capital in an extravagant manner, but when he spends it all, the population of his house must diminish. It must also be noted that Europe is already buying our wood, oil, coal and iron, thus aiding in our eventual industrial impoverishment, to the end that we will be merely the plantation from which its people are to secure bread and meat and the raw materials for their factories - wool, cotton, tobacco, hides, flax, hops.
The 1900 census shows that we are increasing in numbers faster than the food, and such increases cannot continue if we are to export food, for it will all be needed by the factory population. It is estimated that each person uses seven bushels of wheat a year, and, at that rate, 200,000,000 will require double our present crop. It is therefore probable that if we increase beyond 150,000,000 in the next five decades it will only be by reason of wheat importations from Canada and Siberia, a rather unlikely reversal of the present trade.