The interesting fact may now be called to mind that, although many men who lived in Jansen's time were loaded with honors and fame and wealth and glory, the inventor of the telescope and the microscope received no reward of any kind that we know of; and his fame has come to us so imperfectly that we are not even sure that Jansen was his name. The man usually credited with the invention of the telescope is Galileo, though Galileo himself never pretended that he invented it, and though historical statements are clear that he heard that such an instrument had been invented, and then designed and constructed one himself in a day. It would be interesting to know just how much information Galileo received. It seems that his information was very vague. If so, a considerable amount of inventiveness may have been required, besides a high order of constructiveness. But the mere fact that Galileo knew that such an instrument had been invented caused his mental processes to start from an image put into his mind by an outside agency and not from his own imagination. Galileo's work did not begin with conception, and therefore it was not an invention. Galileo was one of the foremost and most ardent supporters of the Copernican Theory; and it was on his skilful and industrious use of the telescope in making observations confirming the theory that his fame mainly rests. As late as 1632, nearly a century after Copernicus's doctrine had become known, Galileo was compelled by threat of torture to recant, and was condemned to imprisonment for life. The influence of inventions on history has been greater and more beneficial than that of any other single endeavor of man. Yet most inventions have been resisted. _The invention of Copernicus was resisted for more than a century by the organization commanding the greatest talent and character and learning that the world contained._ The extraordinary access of mental energy in Europe about the beginning of the seventeenth century is illustrated by another invention virtually contemporaneous with those of Copernicus and Jansen, and also in the line of mathematical research. This was the invention by Baron John Napier of logarithms.