The second into an enquiry as to (_c_), the men who will carry on the farming operations, and (_d_) the implements they will require. The third into (_e_) the kind of work to be planned, and (_f_) where that work is to be done. The fourth into what relates (_g_) to the annual revolution of the sun, and (_h_) the monthly revolution of the moon. I will speak of the four principal parts first, and then in detail of the eight subdivisions. 1° CONCERNING THE FARM ITSELF _How conformation of the land affects agriculture_ VI. Four things must be considered in respect of the physical characteristics of the farm: its conformation, the quality of the soil, its extent, and whether it is naturally protected. The conformation is either natural, or artificial as the result of cultivation, and may be good or bad in either case. I will speak first of natural conformation, of which there are three kinds: plain, hill and mountain--although there is a fourth kind made up of a combination of any two or all three of those mentioned, as may be seen in many places. A different system of cultivation is required for each of these three kinds of farms, for without doubt that which is suited for the hot plain would not suit the windy mountain, while a hill farm enjoys a more temperate climate than either of the other two kinds and so demands its own system of cultivation. These distinctions are most apparent when the several characteristic conformations are of large extent, as for example the heat and the humidity are greater in a broad plain, like that of Apulia, while on a mountain like Vesuvius the climate is usually fresher and so more healthy. Those who cultivate the lowlands feel the effects of their climate most in summer, but they are able to do their planting earlier in the spring, while those who dwell in the mountains suffer most from their climate in winter, and both sow and reap at later seasons. Frequently the winter is more propitious to those who dwell in the plains because then the pastures are fresh there and the trees may be pruned more readily. On the other hand the summer is more kindly in the mountains for then the upland grass is rich when the pastures of the plains are burnt, and it is more comfortable to cultivate the trees in a keen air. A lowland farm is best when it is gently sloping rather than absolutely flat, because on a flat farm water cannot run off and so forms swampy places. But it is a disadvantage to have the surface too rolling because that causes the water to collect and form ponds.