Still, we do not expect that they should be such thorough masters of the subject as to know what stars rise and set together for the different quarters of the earth; those which have the same meridian line, the elevation of the poles, the signs which are in the zenith, with all the various phenomena which differ as well in appearance as reality with the variations of the horizon and arctic circle. With some of these matters, unless as philosophical pursuits, they should not burden themselves at all; others they must take for granted without searching into their causes. This must be left to the care of the philosopher; the statesman can have no leisure, or very little, for such pursuits. Those who, through carelessness and ignorance, are not familiar with the globe and the circles traced upon it, some parallel to each other, some at right angles to the former, others, again, in an oblique direction; nor yet with the position of the tropics, equator, and zodiac, (that circle through which the sun travels in his course, and by which we reckon the changes of season and the winds,) such persons we caution against the perusal of our work. For if a man is neither properly acquainted with these things, nor with the variations of the horizon and arctic circle, and such similar elements of mathematics, how can he comprehend the matters treated of here? So for one who does not know a right line from a curve, nor yet a circle, nor a plane or spherical surface, nor the seven stars in the firmament composing the Great Bear, and such like, our work is entirely useless, at least for the present. Unless he first acquires such information, he is utterly incompetent to the study of geography. *So those who have written the works entitled “On Ports,” and “Voyages Around the World,” have performed their task imperfectly, since they have omitted to supply the requisite information from mathematics and astronomy.*[68] 22. The present undertaking is composed in a lucid style, suitable alike to the statesman and the general reader, after the fashion of my History.[69] By a statesman we do not intend an illiterate person, but one who has gone through the course of a liberal and philosophical education. For a man who has bestowed no attention on virtue or intelligence, nor what constitutes them, must be incompetent either to blame or praise, still less to decide what actions are worthy to be placed on record.