It is absolutely certain that virtually the whole of the influence that printing by movable type has exercised on history sprang from the invention of Gutenberg. It started almost immediately; and it increased with a rapidity and a certainty that are amazing. No invention made before, not even the gun, was seized upon with such avidity. The world wanted it. The world seemed to have been waiting for it, though unconsciously. It may be well at this point to impress upon our minds the fact that no invention has ever been recognized as an invention, unless it has been put into a concrete form. The U. S. Patent Office, for instance, will not award a patent for any invention unless it is described and illustrated so clearly that "any one skilled in the art can make and use it." It is an axiom that a man "cannot patent an idea." In many countries a patentee is required to "work" his invention, to make apparatus embodying it, and to put the apparatus to use. The underlying idea of the patent laws of all countries is that the good of the public is the end in view, and not the good of the inventor; that rewards are held out to the inventor, merely to induce him to put devices of practical value into the hands of the people. From this point of view, which seems to be the correct one, the mere fact that a man conceives of a device, even if he afterward develops his device to the degree that he illustrates it and describes it to someone in such a way that a person skilled in the art can make and use it, does not entitle him to any reward. He must use "due diligence" in communicating full knowledge of his invention to the public, through the Patent Office, ask for a patent, and pay to the Government the prescribed fee. Now, Gutenberg "worked" his invention so energetically that, with the assistance of Faust, Schaeffer and others, an exceedingly efficient system of printing books was in practical operation as early as 1455. The types were of metal, and were cast from a matrix that had been stamped out by a steel punch, and could therefore be so accurately fashioned that the type had a beautiful sharpness and finish. In addition, certain mechanical apparatus of a simple kind (printing presses) were invented, whereby the type could be satisfactorily handled, and impressions could be taken from them with accuracy and quickness. News of the invention spread so rapidly that before the year 1500 printing presses were at work in every country of Europe. The first books printed were, of course, the works of the ancient authors, beginning with three editions of Donatus. These were multiplied in great numbers, and gave the first effective impulse to the spread of civilization from the Græco-Oriental countries, where it had been sleeping, to the hungry intellects of Europe.