But though cultivation cannot be extended, and the produce of the country increased, but in such a state of things as would allow of a rise of rents, yet it is of importance to remark, that this rise of rents will be by no means in proportion to the extension of cultivation, or the increase of produce. Every relative fall in the price of the instruments of production, may allow of the employment of a considerable quantity of additional capital; and when either new land is taken into cultivation, or the old improved, the increase of produce may be considerable, though the increase of rents be trifling. We see, in consequence, that in the progress of a country towards a high state of cultivation, the quantity of capital employed upon the land, and the quantity of produce yielded by it, bears a constantly increasing proportion to the amount of rents, unless counterbalanced by extraordinary improvements in the modes of cultivation. [11] According to the returns lately made to the Board of Agriculture, the average proportion which rent bears to the value of the whole produce, seems not to exceed one fifth; [12] whereas formerly, when there was less capital employed, and less value produced, the proportion amounted to one fourth, one third, or even two fifths. Still, however, the numerical difference between the price of produce and the expenses of cultivation, increases with the progress of improvement; and though the landlord has a less share of the whole produce, yet this less share, from the very great increase of the produce, yields a larger quantity, and gives him a greater command of corn and labour. If the produce of land be represented by the number six, and the landlord has one fourth of it, his share will be represented by one and a half. If the produce of land be as ten, and the landlord has one fifth of it, his share will be represented by two. In the latter case, therefore, though the proportion of the landlord's share to the whole produce is greatly diminished, his real rent, independently of nominal price, will be increased in the proportion of from three to four. And in general, in all cases of increasing produce, if the landlord's share of this produce do not diminish in the same proportion, which though it often happens during the currency of leases, rarely or never happens on the renewal of them, the real rents of land must rise. We see then, that a progressive rise of rents seems to be necessarily connected with the progressive cultivation of new land, and the progressive improvement of the old: and that this rise is the natural and necessary consequence of the operation of four causes, which are the most certain indications of increasing prosperity and wealth--namely, the accumulation of capital, the increase of population, improvements in agriculture, and the high price of raw produce, occasioned by the extension of our manufactures and commerce.