Man's earliest implements were those that lay ready to his hand. A branch from a tree served as a spear; a thick stick in his strong arms became a powerful club. Later, perhaps, came the use of a hard stone such as flint, which could be chipped into the forms of arrowheads, axes, and spear tips. The first stone implements were so rude in shape that it is difficult to believe them of human workmanship. They may have been made several hundred thousand years ago. After countless centuries of slow advance, savages learned to fasten wooden handles to their stone tools and weapons and also to use such materials as jade and granite, which could be ground and polished into a variety of forms. Stone implements continued to be made during the greater part of the prehistoric period. Every region of the world has had a Stone Age. [1] Its length is reckoned, not by centuries, but by milleniums. [Illustration: A HATCHET OF THE EARLY STONE AGE A hatchet of flint, probably used without a helve and intended to fit the hand. Similar implements have been found all over the world, except in Australia.] [Illustration: ARROWHEADS OF THE LATER STONE AGE Different forms from Europe, Africa, and North America.] THE AGE OF METALS The Age of Metals, compared with its predecessor, covers a brief expanse of time. The use of metals came in not much before the dawn of history. The earliest civilized peoples, the Babylonians and Egyptians, when we first become acquainted with them, appear to be passing from the use of stone implements to those of metal. COPPER Copper was the first metal in common use. The credit for the invention of copper tools seems to belong to the Egyptians. At a very early date they were working the copper mines on the peninsula of Sinai. The Babylonians probably obtained their copper from the same region. Another source of this metal was the island of Cyprus in the eastern Mediterranean. The Greek name of the island means "copper." BRONZE But copper tools were soft and would not keep an edge. Some ancient smith, more ingenious than his fellows, discovered that the addition of a small part of tin to the copper produced a new metal--bronze--harder than the old, yet capable of being molded into a variety of forms. At least as early as 3000 B.C. we find bronze taking the place of copper in both Egypt and Babylonia. Somewhat later bronze was introduced into the island of Crete, then along the eastern coast of Greece, and afterwards into other European countries. IRON