Chap. 76.] THE THEOJJY OF THE WINDS. 113 



CHAP. 76. (33.) THE THEORY OF THE WINDS. 



The theory of the winds 62 is of a somewhat more intricate 

 nature. After observing the quarter in which the sun rises 

 on any given day, at the sixth 63 hour of the day take your 

 position in such a manner as to have the point of the sun's 

 rising on your left ; you will then have the south directly 

 facing you, and the north at your back : a line drawn through 

 a field in this direction 64 is called the " cardinal" 65 line. The 

 observer must then turn round, so as to look upon his shadow, 

 for it will be behind him. Having thus changed his position, 

 so as to bring the point of the sun's rising -on that day to the 

 right, and that of his setting to the left, it will be the sixth 

 hour of the day, at the moment when the shadow straight 

 before him is the shortest. Through the middle of this 

 shado\v, taken lengthwise, a furrow must be traced in the 

 ground with a hoe, or else a line drawn with ashes, some 

 twenty feet in length, say ; in the middle of this line, or, in 

 other words, at the tenth foot in it, a small circle must then 

 be described : to this circle we may give the name of the 

 " umbilicus," or " navel." That point in the line which lies 

 on the side of the head of the shadow will be the point from 

 which the north wind blows. You who are engaged in prun- 

 ing trees, be it your care that the incisions made in the wood 

 do not face this point ; nor should the vine-trees 66 or the vines 

 have this aspect, except in the climates of Africa, 67 Cyrense, or 

 Egypt. When the wind blows, too, from this point, you must 

 never plough, nor, in fact, attempt any other of the operations 

 of which we shall have to make mention. 68 



That part of the line which lies between the umbilicus and 

 the feet of the shadow will look towards the south, and indi- 

 cate the point from which the south wind 69 blows, to which, 

 as already mentioned, 70 the Greeks have given the name of 

 Notus. "When the wind comes from this quarter, you, hr.r- 

 bandman, must never fell wood or touch the vine. In Italy 



62 Many of his statements are drawn from Aristotle's Treatise, " De 

 II undo." 63 Our mid-day. 



64 From due north to due south. 6i} Cardo. 



66 " Arbusta." The trees on which the vines were trained. 



67 /. e. the north-west of Africa ; the Roman province so called. 



68 In the next Chapter. 69 Ventus Auster. 

 70 In B. ii. c. 46. 



VOL. IV. I 



