Meanwhile in this period cartography underwent an evolution from ancient to modern methods. It is impossible here to attempt any catalogue of even the principal cartographers, and the work of a few must be taken as typical. In the earlier part of the period (sixteenth century) the marine chart was still the most generally valuable of the cartographer’s wares; but he was already extending his stock in other directions. Thus Gerhard Kremer (1512–94), more famous under the name of Mercator, is principally known for his chart of the world on the familiar rectangular projection which bears his name; but his other activities, besides the production of an atlas, included that of maps of various special areas; and he carried out survey work himself in Flanders as the basis of a map of that territory, which he produced in 1540. Not only the projection named after him, but also the secant conical, are usually attributed to Mercator. Edward Wright, a mathematician of Cambridge, produced the first English map on Mercator’s projection, which indeed has been stated to be actually Wright’s own invention; on this map we should observe the omission of various imaginary and erroneous details common to maps of the period--notably the southern continent. But the renewal of the study of map-projection was mainly owing to German mathematicians, such as Werner of Nuremberg, and Apianus, in the first two decades of the century. In Mercator’s work there are to be observed various tendencies towards modern practice, such as the abolition of the old small sketches or miniatures representing towns and divers other subjects, and the introduction of symbols. On the other hand, the period of the application of criticism by the cartographer to the data before him was not yet come. Mercator was content to supplement data, where imperfect, by imagination; and that tendency is to be observed in other work of the period, as, for example, in the astonishing conception of the hydrography of Africa set forth by F. Pigafetta in 1591. However, the application of criticism and prompt attention to new sources of information soon became recognized as cartographers’ duties. Thus, Nicolas Sanson of Abbeville, who founded a famous map-making establishment in 1627, made a common practice of citing his authorities; and again, promptly upon the work of Jean Picard (noticed above) and others, in the determination of positions from 1669 to the end of the century, there followed the production of a map of France corrected according to these observations, which were also used in other French publications. On some of these appears--first about 1674--the earliest rude representation of relief by hachures, though the old practice of the cartographer, of drawing relief in a species of perspective, and thereby making a molehill on his map out of a mountain in nature, was by no means yet superseded. It was more than half-a-century later that the cartographers hit upon the contour-line. M. S.