For many centuries men believed that the world was a great flat plane, with the habitable earth placed in the midst of an ocean to an almost interminable extent, and that at a certain distance from the land eternal darkness shrouded the waters. Until the old beliefs were abandoned, sailors were reluctant to venture far out of sight of land or into the unknown waters. It is not, therefore, surprising that only slow advances should have been made in the art of navigation. During the middle Ages, ship-building was considerably improved by the Italians, who then conducted extensive maritime trade in the Mediterranean; but the art of navigation was still in its infancy. It really started to develop when the Mariners' compass came into general use, and by the middle of the fourteenth century navigation had assumed a much bolder character than formerly. A traveller whose exclusive purpose is to reach a certain destination in the minimum of time has at once lost half the joy of the journey. He becomes preoccupied with the thought of his goal and this preoccupation makes him intolerant of the friendly advances of those he meets by the way and blind to the ever changing panorama along his route. He resents delay, finds every little inconvenience irksome and frets and fumes at any hitch that threatens to upset his carefully lad plans. There is, it is true, a certain satisfaction in being whirled in comfort through space at breath-taking speeds, or in covering long distances carefree in record time. But the satisfaction is purely material and transitory; there is a touch of vain glorious pride about it; and it smacks too much of business. The real, abiding pleasure of travelling lies in the process, not in the accomplishment. Cookery has always been a science, depending on natural laws such as those that determine the effects of applying a certain degree of heat for a certain period of time to a certain quantity of meat. But it has undoubtedly become an art. In the Middle Age, men undertook long hunting expeditions and returned with enormous appetites; they had to school their stomachs to undergo long periods of fasting and concentrated bouts of feasting.