to be the same, there could be no geometrical increase of the total crop by unassisted nature. The earth has no tendency to increase its surface. There is a tendency of animals and vegetables to increase geometrically, in their quality of living things, but not in their quality of being food for man. The same amount of produce might no doubt be gained on a fresh field, from the seed yielded by the first, and at the same geometrical rate; but this assumes that there is a fresh field, and we should not then be at the proper stage to contrast the two ratios. The contrast begins to show itself as soon as the given quantity of land has grown its crop, and its animal and human population have used all its food. The question is then how any increase of the said population, if they are confined to their own supplies, is at all to be made possible; the answer is, only by greater ingenuity and greater labour in the getting of food; and, however possible this may be, it can hardly be so easy as the increase of living beings by their own act. The degree of disparity between the two will of course depend on the degree of rapidity with which an unchecked population is supposed to double itself. Sir William Petty,[125] with few trustworthy statistics, had supposed ten years; Euler, with somewhat better, twelve and four-fifths; but Malthus prefers to go by the safe figures of the American colonies, which he always regarded as a crucial proof that the period was not more than twenty-five. He admits the risk of his own mathematical simile when he grants that it is more easy to determine the rate of the natural increase of population than the rate of the increase of food which is in a much less degree natural (or spontaneous); and he argues from what had been done in England in his own time that the increase would not even be in an arithmetical ratio, though agricultural improvement (thanks to Arthur Young and the Board of Agriculture, and the long reign of high prices) was raising the average produce very sensibly. If the Napoleonic times were the times of a forced population in England, they were also the times of a forced agricultural production. Yet we ourselves, long after this stimulus, and after much high farming unknown to our fathers, have reached only an average produce of twenty-eight bushels per acre of arable land as compared with twenty-three in 1770,[126] while the population has risen from about six millions to thirty-five. It may be said that applies only to wheat. But until lately wheat-growing was the chief object of all our scientific agriculture; and this is the result of a century’s improvements. It is far from an arithmetical increase; and, even had the produce been multiplied sevenfold, along with the population, this would not overthrow the contention of Malthus, for he is not speaking of any and every increase of food, but of such an increase made by the same methods and by the same kind of labour as raised the old supplies.[127] Once it