2651ページ中463ページ

Rent, even where coals afford one, has generally a smaller share

in their price than in that of most other parts of the rude

produce of land. The rent of an estate above ground, commonly

amounts to what is supposed to be a third of the gross produce;

and it is generally a rent certain and independent of the

occasional variations in the crop. In coal mines, a fifth of the

gross produce is a very great rent, a tenth the common rent; and

it is seldom a rent certain, but depends upon the occasional

variations in the produce. These are so great, that in a country

where thirty years purchase is considered as a moderate price for

the property of a landed estate, ten years purchase is regarded

as a good price for that of a coal mine.