Now the men of the Renaissance took a great interest in those mechanical inventions which had long been in use in ancient China. "Discovered over and over again, and offered to the human race at various times and on divers soils, no effective use was made of these material resources till the end of the fifteenth century," when the Renaissance was in full tide (Symonds "Renaissance in Italy").
The art of printing, like the making of paper, had long been known to the Chinese, but it was not till about 1450 that printing was used in Europe, John Gutenberg of Mainz being the first to print from movable metal type. Hitherto all Western books had been "manuscripts " -- i.e. written by hand, like those of the Florentine library. And manuscript books were very costly and confined to the few. Soon, however, printing presses were busy spreading the new ideas.
The great printers of Venice, with their 200 presses, were soon publishing fine copies of the old Greek books; and the printers of Basle were soon busy with the works of Erasmus. Gradually books became cheaper and possible for all, and this had far-reaching results. "In the Middle Ages the Church -- that is to say, first the cloister, then the universities founded under the protectorate of the Church -- had the civilizing of society and the monopoly of literature;" but that came to an end when the clergy had to share their knowledge and influence with the laymen. It is no wonder that the invention of printing has been called the greatest event in history.
Again, gunpowder -- invented, like printing, long ago by the Chinese, and used in Europe from about 132O -- gradually changed the art of war. The feudal castle, the knight's armour and his battle horse, the prowess of one man against a hundred, lost their significance with the invention of cannon.
Finally, the mariner's compass -- invented about 1302, and used by Columbus on his voyage to America -- at last enabled men to travel more safely on unknown seas.