For instance, a man owning a farm and tilling it himself gets a harvest of 1,000 sacks of wheat. In order to get this result he must have capital at the beginning of every year--ploughs and horses, and sacks of grain and what not--worth altogether 10,000 sacks of wheat. His income, in wheat, is one-tenth of his capital. Every ten sacks of capital produces him an income of one sack a year. He says to himself: “If I were to plough the land more thoroughly and put on a lot more phosphates and slag and get new, improved machinery I might get another fifty sacks a year out of the land, but this new capital will have to be saved.” He carefully saves on every harvest, exchanging the wheat for the things he needs in the way of new capital, until, after a few years, the implements and the phosphates and slag and the rest on his land, and all his other capital is worth much more than it used to be. Instead of being worth only _one_ thousand sacks, his capital is now worth _two_ thousand sacks, and he gets the reward for his putting by and doing without immediate enjoyment in the shape of a larger harvest. But though he has doubled his capital he has not doubled his income. Instead of the old income of 100 sacks of wheat he is now getting 150 sacks of wheat. Thus though his income is larger, the _proportion_ of that income to the total capital is less. For 1,000 sacks of capital he got 100 sacks of wheat at harvest; but now for 2,000 sacks of capital he only gets 150 sacks at the harvest. Or (as we put it in modern language), his income is no longer 10 per cent. on his capital, but 7½ per cent. only. He has a larger income, but it is smaller in proportion to the capital invested. Now, although the 2,000 of capital invested is thus bringing him in a smaller _proportion_ of income than the old 1,000 did, he thinks it worth while: because he is at any rate getting more _income_; 150 sacks instead of only 100. But there must come a time when he will no longer think it worth while to go on saving. Supposing he finds, for instance, that after taking all the trouble to accumulate and apply to his land capital to the value of 10,000 sacks of wheat, he gets only 200 sacks, that is 2 per cent. annual reward for all this saving, he will not think it good enough, and he will stop saving. The point where he stops, the return below which he does not think it worth while to save, marks the _minimum profits of capital_. A man is delighted, of course, to have _more_ profit than this if he can. But the point is, he will not take _less_. Rather than make less than a certain proportion of income to his capital he will stop saving, and spend all he has in immediate enjoyment.