A Trade Revolution

From the time when primitive man first went adrift on a bundle of reeds or learnt to balance himself on a floating log, to the days where his descendants, no more than a few generations ago, raced scrambling aloft to trim the towering sails of a full-rigged ship, the skill of the sailor remained the same: the application of the forces of nature in wind, tide, current and human muscles to the propulsion of his craft.

Throughout this long period, although the principle involved remained unaltered, the ingenuity of man brought about a number of developments of even wider scope and more far-reaching importance than in the case of travel on land. Prior to the seventeenth century...