Both in the case of mines and of fisheries, the natural order of events is liable to be interrupted by the opening of a new mine, or a new fishery, of superior quality to some of those already in use. In this case, when things have permanently adjusted themselves, the result will be that the scale of qualities which supply the market will have been cut short at the lower end, while a new insertion will have been made in the scale at some point higher up; and the worst mine or fishery in use—the one which regulates the rents of the superior qualities and the value of the commodity—will be a mine or fishery of better quality than that by which they were previously regulated. The ground-rent of a building, and the rent of a garden or park attached to it, will not be less than the rent which the same land would afford in agriculture, but may be greater than this to an indefinite amount; the surplus being either in consideration of beauty or of convenience, the convenience often consisting in superior facilities for pecuniary gain. Sites of remarkable beauty are generally limited in supply, and therefore, if in great demand, are at a scarcity value. Sites superior only in convenience are governed as to their value by the ordinary principles of rent. The ground-rent of a house in a small village is but little higher than the rent of a similar patch of ground in the open fields. Suppose the various kinds of land to be represented by the alphabet; that those below O pay no agricultural rent, and that all lands increase in fertility and situation as we approach the beginning of the alphabet, but which, as far up as K, are used in agriculture; that higher than K all are more profitably used for building purposes, viz.: A, B, C, ... | K, L, M, N, O, | ... X, Y, Z. Now it will happen that land is chosen for building purposes irrespective of its fertility for agricultural purposes. It will not be true, as some may think, that no land will be used for building until it will pay a ground-rent greater than the greatest agricultural rent paid by any piece of land. It is not true, for example, if N be selected for a building-lot, that it must pay a ground-rent as high as the agricultural rent of K, the most fertile land cultivated in agriculture. It must pay a ground-rent higher only than it itself would pay, if cultivated. It is only necessary that it pay more than the same (not better) land would pay as rent if used only in agriculture.