Fifthly, it is evident that the price of the waterfall, that is, the price which the landowner would receive were he to sell it to a third party or even to the manufacturer himself, does not immediately enter into the production price of the commodities, although it does enter into the individual cost-price of the manufacturer; because the rent arises here from the price of production of similar commodities produced by steam machinery, and this price is regulated independently of the waterfall. Furthermore, this price of the waterfall on the whole is an irrational expression, but behind it is hidden a real economic relationship. The waterfall, like land in general, and like any natural force, has no value because it does not represent any materialised labour, and therefore, it has no price, which is normally no more than the expression of value in money terms. Where there is no value, there is also eo ipso nothing to be expressed in money. This price is nothing more than the capitalised rent. Landownership enables the landowner to appropriate the difference between the individual profit and average profit. The profit thus acquired, which is renewed every year, may be capitalised, and appears then as the price of the natural force itself. If the surplus-profit realised by the manufacturer using the waterfall amounts to £10 per year, and the average interest is 5%, then these £10 represent the annual interest on a capital of £200 and the capitalisation of the annual £10 which the waterfall enables its owner to appropriate from the manufacturer, appears then as the capital-value of the waterfall itself. That it is not the waterfall itself which has value, but that its price is a mere reflection of the appropriated surplus-profit capitalistically calculated, becomes at once evident from the fact that the price of £200 represents merely the product obtained by multiplying a surplus-profit of £10 by 20 years, whereas, other conditions remaining equal, the same waterfall will enable its owner to appropriate these £10 every year for an indefinite number of years — 30 years, 100 years, or x years; and, whereas, on the other hand, should some new method of production not applicable with water-power reduce the cost-price of commodities produced by steam machinery from £100 to £90, the surplus-profit, and thereby the rent, and thus the price of the waterfall, would disappear.