Another part of the capitalist's so-called profit ought to be laid aside as #recompense for risk#. There is always more or less uncertainty in trade, and even the most skilful and careful manager may lose money by circumstances over which he has no control. Sometimes, after building a factory, the demand for the goods which he is going to produce falls off; sometimes the materials cannot be bought; perhaps it is discovered, when too late, that the factory has been built in an unsuitable place; occasionally, too, the workmen are discontented, and refuse to work for such wages as the capitalist can afford to pay. Now, whenever any of these mistakes or misfortunes happen, it is the capitalist who mainly suffers, because he loses a great deal of money, on which he might otherwise have lived comfortably. Sometimes men who have worked hard all their lives, and grown rich by degrees, lose all their wealth again in the end, by some error of judgment or by some unfortunate event due to no fault of their own. A capitalist, then, must have some inducement for running into these disagreeable risks; by lending his capital to the government he might get interest for it, and be nearly sure not to lose. If, then, he puts it into trade, and runs the risk of loss, he must have a recompense for the risk. This ought to be at least enough to make the profits of the successful business balance the losses of the unfortunate ones, so that on the average capitalists will get the interest of capital and the wages of superintendence free from loss. We may say, then, that-- profit = wages of superintendence + interest + recompense for risk. #42. About Interest.# That which is paid for the use of capital altogether apart from what is due for the trouble and risk of the person conducting the business, is called #interest#. This interest, of course, will be greater or less according as the amount of capital is greater or less; it will also be greater or less according as the capital is employed for a longer or shorter time. Thus the rate of interest is always stated in proportion to the capital sum and to the time; _five per cent. per annum_ means that, for every hundred pounds of capital, five pounds are paid during every year in which the capital is used, and in the same proportion for longer or shorter times.