Adapted from Early European History by Hutton Webster (1917) 

The prehistoric period is commonly divided, according to the character of the materials used for tools and weapons, into the Age of Stone and the Age of Metals. The one is the age of savagery; the other is the age of barbarism or semi-civilization.

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, early people 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.  Its length is reckoned, not by centuries, but by millennia.

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 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." 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 BCE 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.

The introduction of iron occurred in comparatively recent times. At first it was a scarce, and therefore a very precious, metal. The Egyptians seem to have made little use of iron before 1500 BCE They called it "the metal of heaven," as if they obtained it from meteorites. In the Greek Homeric poems, composed about 900 BCE or later, we find iron considered so valuable that a lump of it is one of the chief prizes at athletic games. In the first five books of the Bible iron is mentioned only thirteen times, though copper and bronze are referred to forty-four times. Iron is more difficult to work than either copper or bronze, but it is vastly superior to those metals in hardness and durability. Hence it gradually displaced them throughout the greater part of the Old World.

Why does the author think it is “difficult to believe [the first stone tools were] of human workmanship"?

Adapted from Ten Great Events in History by James Johonnot (1887)

Following the Council of Clermont, preparations for invading the Holy Land began in almost every country of Europe. The nobles mortgaged their estates, the farmer endeavored to sell his plow, and the artisan his tools to purchase a sword. During the spring and summer of 1096, the roads teemed with crusaders, all hastening to the towns and villages appointed as the rendezvous of the district. Very few knew where Jerusalem was. Some thought it fifty thousand miles away, and others imagined it but a month's journey; while at the sight of every tower or castle the children exclaimed "Is that Jerusalem?" 

Little attempt at any organization was made, though the multitude had three leaders. It is said that the first band, consisting of twenty thousand foot, with only eight horsemen, were led by a Burgundian gentleman called Walter the Penniless. They were followed by a rabble of forty thousand men, women, and children led by Peter the Hermit. Next followed a band of fifteen thousand men, mostly Germans, under a priest named Gottschalk.

Like their nominal leader, each of the followers of Walter the Penniless was poor to penury, and trusted for subsistence to the chances of the road. In Hungary, they met with loud resistance from the people, whose houses they attacked and plundered, but in Bulgaria, the natives declared war against the hungry horde; they were dispersed and almost exterminated. Some, including Walter, reached Constantinople, where they awaited Peter and his companions. The Hermit, who had the same difficulties to contend with in marching through Hungary and Bulgaria, reached Constantinople with his army greatly reduced, and in a most deplorable condition. Here he and Walter joined forces. They were hospitably received by the emperor, but their riotous conduct soon wearied out his patience, and he was glad to listen to a proposal to help them at once pass into Asia. 

The rabble accordingly crossed the Bosphorus, and took up their quarters in Bethynia. Here they became perfectly ungovernable, ravaging the country around, and committing incredible excesses; at length Peter, utterly disgusted and despairing, left them to their own guidance and returned to Constantinople. The bravest of them were annihilated in a battle fought near Nice, Walter the Penniless falling with seven mortal wounds. Between two and three thousand alone escaped. The emperor dismissed them, with orders to return home, and thus ended the disastrous expedition of Walter the Penniless and Peter the Hermit.

The fifteen thousand Germans led by Gottschalk never reached Constantinople, being slaughtered or dispersed during their passage through Hungary. Thus, within a few months, upward of a quarter of a million of human beings were swept out of existence. And they had spent their lives, without one important result having been accomplished. This was the worst paroxysm of the madness of Europe.

Can we infer is the main reason for the failure of the first crusades described in the passage, according to the author?