he had lent it upon good security; and, secondly, to keep the house in constant repair, or, what comes to the same thing, to replace, within a certain term of years, the capital which had been employed in building it.

The building-rent, or the ordinary profit of building, is, therefore, everywhere regulated by the ordinary interest of money. Where the market rate of interest is four per cent the rent of a house which, over and above paying the ground-rent, affords six or six and a half per cent upon the whole expense of building, may perhaps afford a sufficient profit to the builder. Where the market rate of interest is five per cent, it may perhaps require seven or seven and a half per cent. If, in proportion to the interest of money, the trade of the builder affords at any time a much greater profit than this, it will