In the history of Herodotus, there is an account of a map constructed by Aristagoras, tyrant of Miletus, when he proposed to Cleomenes, king of Sparta, to attack Darius, king of Persia, at Susa; from this account, the vague, imperfect, and erroneous ideas entertained in his time of the relative situations and distances of places, as well as of the extremely rude and feeble advances which had been made towards the construction of maps, may be inferred. Major Rennell, in his Illustrations of Herodotus, has endeavoured to ascertain from his history the parallel and meridian of Halicarnassus, the birth-place of the historian. According to him, they intersect at right angles over that town, cutting the 37th degree of north latitude, and the 45-1/2 of east longitude, from the Fortunate Islands. For a considerable period after the time of Herodotus, the ancients seem to have been nearly stationary in their knowledge of the world. About 368 years before Christ, Eudoxus, of Cnidus, whose desire of studying astronomy induced him to visit Egypt, Asia, and Italy, who first attempted to explain the planetary motions, and who is said to have discovered the inclination of the moon's orbit, and the retrograde motion of her nodes, is celebrated as having first applied geographical observations to astronomy; but he does not appear to have directed his researches or his conjectures towards the figure or the circumference of the earth, or the distances or relative situations of any places on its surface.