The Age of Iron succeeded the Age of Bronze in the countries from which we have inherited our civilization; but in Africa bronze does not seem to have been discovered until after iron was. Iron being an element like copper, and not an alloy of two metals like bronze, it seems probable that its discovery, like that of copper, followed the act of heating stones with fire. The coming of iron seems due therefore to discovery rather than to invention; but yet the mere discovery that a very hard substance had been accidentally produced would of itself have brought forth no fruit. One is almost forced to infer from probability that the fact must have become known to many men, but only as a plain and uninteresting fact. Finally, some man realized that that hard substance was superior to bronze for making weapons, and then set to work to ascertain exactly what kinds of stone it could be gotten from, and exactly what process gave the best results. To us who have been carefully taught the facts known at the present day, and whose minds have been trained by logic and mathematics to reason from effect to cause, and to construct frameworks of cause wherefrom to gain effects, it seems that anyone who noted that the hard substance which we call iron came from heating certain stones, would immediately invent a process for making iron in quantities. But prehistoric man had no knowledge whatever save that coming from his own observation and the oral teachings of the wise men; mathematics and logic did not exist; and the only training given him was in those simple arts of hunting, fishing, field tilling, etc., by which he earned his livelihood. For a mind so untrained and ignorant to leap from the simple noting of the accidental production of the metal to a realization of its value, then to a correct inference as to the possibility of producing it at will, then to a correct inference as to the method of producing it, and then to devising the method and actually producing iron at will, suggests a reasoning intelligence of an order exceedingly high. Nevertheless, the art of making iron may have originated not so much from effort as from inspiration; the process may have been less one of reasoning than one of imagination, less one of construction than one of invention. In fact, when we realize that imagination is almost wholly a pure gift (like beauty, or artistic genius or a singing voice) while the reasoning and constructive faculties require long education, we may reasonably conclude that the production of iron and of all the metals and processes in prehistoric times, was probably attributable mainly to invention.