We have already stated[1] that the umbilicus should be described in the middle of the line. Let another line be drawn transversely through the middle of it, and it will be found to run from due east to due west; a trench cut through the land in accordance with this line is known by the name of "decumanus." Two other lines must then be traced obliquely across them in the form of the letter X, in such a way as to run exactly from right and left of the northern point to left and right of the southern one. All these lines must pass through the centre of the umbilicus, and all must be of corresponding length, and at equal distances. This method should always be adopted in laying out land; or if it should be found necessary to employ it frequently, a plan[2] of it may be made in wood, sticks of equal length being fixed upon the surface of a small tambour,[3] but perfectly round. In the method which I am here explaining, it is necessary to point out one precaution that must always be observed by those who are unacquainted with the subject. The point that must he verified first of all is the south, as that is always the same; but the sun, it must be remembered, rises every day at a point in the heavens different to that of his rising on the day before, so that the east must never be taken as the basis for tracing the lines.

Having now ascertained the various points of the heavens, the extremity of the line that is nearest to the north, but lying to the east of it, will indicate the solstitial rising, or, in other words, the rising of the sun on the longest day, as also the point from which the wind Aquilo[4] blows, known to the Greeks by the name of Boreas. You should plant all trees and vines facing this point, but take care never to plough, or sow corn, or plant in seed plots, while this wind is blowing, for it has the effect of drying up and blasting the roots of the trees while being transplanted. Be taught in time—one thing is good for grown trees, another for them while they are but young. Nor have I forgotten the fact, that it is at this point of the heavens that the Greeks place the wind, to which they give the name of Cæcias; Aristotle, a man of most extensive learning, who has assigned to Cæcias this position, explains that it is in consequence of the convexity of the earth, that Aquilo blows in an opposite direction to the wind called Africus.

The agriculturist, however, has nothing to fear from Aquilo, in respect to the operations before mentioned, all the year through; for this wind is softened by the sun in the middle of the summer, and, changing its name, is known by that of Etesias.[5] When you feel the cold, then, be on your guard; for, whatever the noxious effects that are attributed to Aquilo, the more sensibly will they be felt when the wind blows from due north. In Asia, Greece, Spain, the coasts of Italy, Campania, and Apulia, the trees that support the vines, as well as the vines themselves, should have an aspect towards the north-east. If you wish to have male produce, let the flock feed in such a way, that this wind may have the opportunity of fecundating the male, whose office it is to fecundate the females. The wind Africus, known to the Greeks by the name of Libs, blows from the south-west, the opposite point to Aquilo; when animals, after coupling, turn their heads towards this quarter,[6] you may be sure that female produce has been conceived.

The third[7]: line from the north, which we have drawn transversely through the shadow, and called by the name of "decumanus," will point due east, and from this quarter the wind Subsolanus blows, by the Greeks called Apeliotes. It is to this point that, in healthy localities, farm-houses and vineyards are made to look. This wind is accompanied with soft, gentle showers; Favonius, however, the wind that blows from due west, the opposite quarter to it, is of a drier nature; by the Greeks it is known as Zephyrus. Cato has recommended that olive-yards should look due west. It is this wind that begins the spring, and opens the earth; it is moderately cool, but healthy. As soon as it begins to prevail, it indicates that the time has arrived for pruning the vine, weeding the corn, planting trees, grafting fruit-trees, and trimming the olive; for its breezes are productive of the most nutritious effects.

The fourth[8] line from the north, and the one that lies nearest the south on the eastern side, will indicate the point of the sun's rising at the winter solstice, and the wind Volturnus, known by the name of Eurus to the Greeks. This wind is warm and dry, and beehives and vineyards, in the climates of Italy and the Gallic provinces, should face this quarter. Directly opposite to Volturnus, the wind Corus blows; it indicates the point of the sun's setting at the summer solstice, and lies on the western side next to the north. By the Greeks it is called Argestes, and is one of the very coldest of the winds, which, in fact, is the case with all the winds that blow from the north; this wind, too, brings hailstorms with it, for which reason it is necessary to be on our guard against it no less than the north. If Volturnus begins to blow from a clear quarter of the heavens, it will not last till night; but if it is Subsolanus, it will prevail for the greater part of the night. Whatever the wind that may happen to be blowing, if it is accompanied by heat, it will be sure to last for several days. The earth announces the approach of Aquilo, by drying on a sudden, while on the approach of Auster, the surface becomes moist without any apparent cause.