I HISTORICAL SKETCH I A little more than four hundred years ago, when Europe was emerging from the darkness of the Middle Ages into the era of printed books, when the Field of the Cloth of Gold had impressed the official stamp of culture on her civilization, when gunpowder was changing the aspect of war—in an age that produced such intellects as those of Machiavelli, Copernicus, Lorenzo the Magnificent, Cardinal Wolsey, and John Werner—wise men were still groping blindly for knowledge about the world in which they lived that is regarded as elementary by the school children of our day. What was its shape? What lay beyond the western horizon of the Atlantic, the vast and stormy _Mare Tenebrosum_ of fabled terror to mariners? What was south of the African countries bordering the Mediterranean? How far east did Asia extend? No one knew. In the year 150 A.D., the learned Alexandrian Claudius Ptolemy had made a map of Europe and of those parts of Asia and Africa which were then known, or supposed to exist; and on that map, for the first time in history, the world was represented as a sphere—_though a stationary one_. Therefore, speculated those who thought about it at all, assuming Ptolemy’s theory to be correct, how could a mariner, even were he successful in navigating his vessel down the awful declivity on one side of the globe, hope to make it climb up again on the other? How could he cross the equator, which Aristotle and Pliny had declared was an uninhabitable zone, so torrid that the earth around was burnt up as with fire and only marine salamanders, if such monsters existed, could live in the super-heated waters? And, even if the equator were passable, how could the frightful abysses into which the ocean was supposed to discharge itself at the pole be escaped? Some time in the sixth century a monk named Cosmas had attempted to answer these questions by means of a theory evolved from a study of the Bible and more consistent with its descriptions and metaphors. In the map he made, the world was represented as a level rectangle, its sides composed of blue walls, supporting a dome that separated the mortal domain from the Paradise where dwelt the Creator and his angels; and, fanciful as was this cosmos of Cosmas’ devising, his map was regarded as the standard of geographical knowledge down to the time of Columbus. Even after his time the famous astronomer Galileo was imprisoned as a heretic partly for reasserting the theory of Ptolemy. No one but a few scientists even imagined that the east could be reached by sailing west; no one, not even they, yet knew that Africa could be circumnavigated and the treasures of gorgeous Far Cathay (as China was then called) brought to Europe’s doors by water. _Yet it was to accomplish that very object that the series of voyages was begun that led eventually to the discovery of America._