ments made of this amalgam a sharp edge. Before this discovery cutting implements made of pure copper had been tried, but they were little better than those made of stone. This preliminary metallic stage—the so-called Copper Age—was not of long duration. It was otherwise with bronze, as its superior qualities for cutting and penetrating purposes became at once apparent. But its general application to the arts and industries was a somewhat slow process, especially in outlying districts, such as Britain, where the new tools and implements had, in the first instance, to be imported at heavy expense. The transition from a lower stage of culture to a higher one involves a series of minor innovations on old customs and mechanical usages, which vary in the course of time in different countries. Hence, the line of demarcation between the different ages is not sharply defined, the result of which is that many of the stone implements formerly in use survived in out-of-the-way districts long after the introduction of their analogues in metal.
Man is not unfrequently defined as a toolmaker, a definition which has the advantage of placing him in a category which excludes all other animals. In virtue of this monopoly he has practically discarded the natural means of self-preservation, with which Nature endowed him, and substituted in lieu of them all sorts of tools and appliances manufactured by his own hands. These mechanical inventions, or rather such of them as have
