All these advantages attach to the land; it is on this land and no other that they can be utilized, for here is the center of population—the focus of exchanges, the market place and workshop of the highest forms of industry. The productive powers which density of population has attached to this land are equivalent to the multiplication of its original fertility by the hundred fold and the thousand fold. And rent, which measures the difference between this added productiveness and that of the least productive land in use, has increased accordingly. Our settler, or whoever has succeeded to his right to the land, is now a millionaire. Like another Rip Van Winkle, he may have lain down and slept; still he is rich—not from anything he has done, but from the increase of population. There are lots from which for every foot of frontage the owner may draw more than an average mechanic can earn; there are lots that will sell for more than would suffice to pave them with gold coin. In the principal streets are towering buildings, of granite, marble, iron, and plate glass, finished in the most expensive style, replete with every convenience. Yet they are not worth as much as the land upon which they rest—the same land, in nothing changed, which when our first settler came upon it had no value at all. That this is the way in which the increase of population powerfully acts in increasing rent, whoever, in a progressive country, will look around him, may see for himself. The process is going on under his eyes. The increasing difference in the productiveness of the land in use, which causes an increasing rise in rent, results not so much from the necessities of increased population compelling the resort to inferior land, as from the increased productiveness which increased population gives to the lands already in use. The most valuable lands on the globe, the lands which yield the highest rent, are not lands of surpassing natural fertility, but lands to which a surpassing utility has been given by the increase of population. The increase of productiveness or utility which increase of population gives to certain lands, in the way to which I have been calling attention, attaches, as it were, to the mere quality of extension. The valuable quality of land that has become a center of population is its superficial capacity—it makes no difference whether it is fertile, alluvial soil like that of Philadelphia; rich bottom land like that of New Orleans; a filled-in marsh like that of St. Petersburg, or a sandy waste like the greater part of San Francisco.