It was naturally a great shock to men to have it suggested that their dwelling place, instead of being God's greatest work to which He had subordinated everything, was but a tiny speck in comparison to the whole universe, and its sun but one of an innumerable host of similar bodies, each of which might have its particular family of planets revolving about it. Theologians, both Protestant and Catholic, declared the statements of Copernicus foolish and wicked and contrary to the teachings of the Bible. He was prudent enough to defer the publication of his great work until just before his death; he thus escaped any persecution to which his discovery might have subjected him. [Sidenote: Miscellaneous inventions.] In addition to the various forms of progress of which we have spoken, the fourteenth and fifteenth centuries witnessed the invention or wide application of a considerable number of practical devices which were unknown to the Greeks and Romans. Examples of these are, besides printing, the compass, gunpowder, spectacles, and a method of not merely softening but of thoroughly melting iron so that it could be cast. [Sidenote: The fourteenth and fifteenth centuries not merely a period of revival.] The period of which we have been speaking was, in short, by no means merely distinguished for the revival of classical learning. It was not simply a re-birth of the ancient knowledge and art, but a time during which Europe laid the foundations for a development essentially different from that of the ancient world and for achievements undreamed of by Aristotle or Pliny.