Now, then, since commodities of the second class in the cost of their production must respond not only to the _current_ cost of Labor and Capital in bringing them to market, but also something additional in the way of Rent to the _past_ cost of the implement, the land-parcel, without whose contributing agency present results could not be gained; _Rent is the Rendering for the present use of a Valuable made such by past Labor and Capital._ Land-parcels leased for agriculture; mines and the access to them leased for the production of metals and minerals; and forests whose growth has been permitted by the past _abstinence_ of their owners; all properly yield a rent; because these forms of capital, whose existence is due to past labor and capital, are present contributors to products, whose sale must compensate not only present labor and the use of current capital, but also the use of these more permanent forms of capital long ago created. A competent authority estimated in 1881, that the land-parcels of the United Kingdom of Great Britain were worth £3,000,000,000; and there were at the same time 6,000,000 of inhabited houses, excluding factories and business premises and tenements renting for £20 and under. Most of these lands and houses are rented by their owners to the actual occupiers on the just principle explained above, inasmuch as the lease-system is the prevailing one in that country. According to the Census of 1880, there were 4,008,907 so-called farms in the United States in that year. Most of these are held in fee simple, and are tilled by their owners; but just so far as land-patches and forests and mines are leased in this country, their products must provide in their price of sale for current rents, as well as current costs of present production. This is just as it should be, and just as it must be, if Capital is to take this form of assisting the processes of future production.