The invention of printing from movable types is second only to the clock in its critical effect upon our civilization; and in its own right exemplifies the much broader passage, constantly going on in our own day, from the tool to the hand-worked machine. Probably many people in this audience know, at least in outline, the story of printing, so admirably put together by Thomas Carter, the veritable unraveling of a mystery from which only the very last link in the chain seems still to be absent. Printing swept across the world, from China and Korea, where movable types were first invented, into Europe, in the course of a century. Printing broke the class monopoly of the written word, and it provided the common man with a means of gaining access to the culture of the world, at least, all of that culture as had been translated into words or other printable symbols.