In a great bee-hive like modern China, where men swarm in countless millions, work is not only done cheaper, it is done better than among the poor and scanty tribes that peopled the shores and narrow valleys of Greece and Italy in those remote days when Memphis and Babylon were still great capitals. These small clans of fishermen and woodmen, of shepherds and agriculturists, were cut off from one another by lofty ridges, which were often to be crossed only by difficult and dangerous paths. A happy chance or a well directed effort of thought might lead one of them to discover some technical secret, but a long time would elapse before the invention would cross the mountains and simplify the toil of the neighbouring tribes. In that western world which remained so restless until the eleventh or tenth century before our era, it constantly happened that a tribe was bitten by a kind of mania to seek for a new and more favourable home. These displacements put an end to labour for a time, and brought about shocks and conflicts by which development was arrested and settled questions reopened. A canton sacked or a few villages destroyed was enough to put an end to some promising invention or to destroy the memory of some successful process. No conquest over natural difficulties was final. It was quite otherwise in those ancient states which had a population firmly rooted in the soil, and of industrious, sedentary habits. In such societies there was no danger of a rude interruption to a work begun. When some artizan more skilful or imaginative than his fellows improved the tools of his trade, the knowledge of those improvements spread rapidly from workshop to workshop. Even in the cities of the modern East those who follow a particular trade live together in their own quarter of the town. In Constantinople and Cairo, in Damascus and Bagdad, there is the armourers’ quarter, the jewellers’ quarter, that of the saddlers, the tailors, and of many others. These quarters have their own special entrances, their officers and watchmen; in the days of antiquity as now, they formed so many small industrial towns, where, thanks to the heredity of professions and the constancy of habits and fashions, the prosperity of the manual arts was not at the mercy of political accident. Wars and changes of dynasty might cause a moment of stagnation and dulness, but such troubles did not prevent the apprentice from receiving from his master the instruction in his trade that he would afterwards pass on to his successors, with all that he himself could add to the legacy of the past. There were no sudden interruptions, no solutions of continuity: all that was found was kept; nothing was forgotten or wasted.