Limitations of stone tools
- Related Topics:
- eolith
- kodali
- core tool
- ground tool
- microlith
The possibilities in the design of rock tools were limited by the inflexibility and brittleness of the material. The design effort was constrained to the sizing of the tool to the intended task and the development of sharper, longer, and more usefully shaped cutting edges that always required backing to support them. In use, the bending and twisting of long knifelike tools had to be avoided lest the action destroy them; this would also have been true of chisels and gouges. Similarly, even the much later heavier tools, such as the ax and adz, required care in use.
The effectiveness of rock tools has been demonstrated from time to time by both archaeologists and modern workers unaccustomed to such tools. An experienced operator using a rock knife can skin a small animal about as quickly and deftly as he can using steel. When the rock tool is subjected to substantial forces, however, the worker must use caution, intelligence, and control. Care is required to avoid twisting or prying with a rock blade (knife or ax); a thin blade may snap, and a thick one may collect local nicks.
Paleolithic tools
Early tools are classified by their industry, or type of workmanship. Such tool traditions are identified by a name derived from the site at which the type first drew archaeological attention. For example, the primitive chopping tools that persisted for nearly 2 million years, first identified in Olduvai Gorge, east of Lake Victoria, Tanzania, constitute the so-called Oldowan industry, regardless of the part of the world in which implements of similar workmanship happen to be found.
The sequence of traditions shows growth and development; it does not imply abrupt transitions at certain times or the disappearance of an old industry with the advent of another. A new technique simply meant that something better or different could be accomplished, from the refinement of the cutting edge or the upgrading of old tool forms to the manufacture of a completely new tool. Innovation sometimes was possible only by drawing upon previously unworkable materials.
An overview of the products of the successive toolmaking industries shows that much effort went into cutting edges in the longitudinal direction of the pieces of flint. Knifelike instruments predominated and thus defined the nature of the fundamental need—namely, that of a cutting tool which could slit and sever.
With the passage of time and the acquisition of skills, the average size of the tool decreased; there was more cutting edge per pound of material, an important factor when flint had to be imported to a region. This trend was reversed in the Neolithic Period, when the heavy woodsman’s ax and adz became essential elements for clearing forests for agriculture and timber. The world was then changing from an economy based on gathering and hunting food to a way of life founded on raising food.
Archaeologists have named the early tools by guessing at their presumed use, often in the light of other known facts about the culture in which the tradition appeared. As the tools move closer to the present, and specialized forms are seen in the creation of a wider variety of products, the descriptive name is on firmer ground.
Eoliths
The first act of the drama of tools is hazy. There are what have been called eoliths, “tools from the dawn of the Stone Age.” Such stones with sharp fractures, found in great quantities in layers from the geological epochs before the Pleistocene, were once assumed to be tokens of human presence in the preceding Pliocene and even earlier Miocene epochs. These rocks, fractured by glacier pressure, wave action, or temperature change, are no longer taken as indexes of humans, although primitive peoples undoubtedly used them as ready-made objects before they deliberately started to fracture similar rocks in the late Pliocene. There are detailed criteria by which human-flaked and nature-flaked stones can be almost unerringly distinguished. Human origin is also evidenced by association with detached flakes and the stones that served as hammers.
The oldest known tools—consisting of primitive hammers, anvils, and cutting tools and dating to 3.3 million years ago—were discovered in 2011 and 2012 at the Lomekwi 3 site near Kenya’s Lake Turkana (Lake Rudolf). Tools found in 1969 at the Koobi Fora site, near Lake Turkana, consisted of five choppers, a number of flakes, and a couple of battered stones. The tools lay on the surface; the flakes were found three feet below them in tuff (volcanic rock) datable to about 2.6 million years ago. Artifacts known from Olduvai Gorge, Tanzania, included tools, as well as the jaw and teeth of a human who may have been the toolmaker. These items were found in the 1950s under tuff having a potassium-argon date of about 1.8 million years, a Lower Pleistocene age.
All of these tools are of a single type, a general-purpose implement that changed little in form during the next 2 million years. It is variously known as a pebble tool, pebble chopper, chopping tool, or simply as a chopper. Waterworn and hence rounded, up to about the size of a fist, the pebble, preferably flattish rather than spherical, was given a few violent but skillfully applied blows by a hammerstone. Several large flakes or chips were knocked off the rock to create on it a sharp and roughly serrated crest, or ridge, yielding an implement that was edged at one end and could be gripped at the opposite end. Rudimentary yet versatile, the chopper could be used to hack, mash, cut, grub roots, scrape, and break bones for their marrow.
Although the large sharp-edged flakes struck from the pebble were themselves useful for light cutting and scraping, it was not until perhaps 40,000 years ago that there was a development of flake tool industries in which preshaped flakes were purposefully detached from a core that was then discarded. But the Oldowan chopper and the struck-off flakes—the earliest generalized primitive tools—between them solved the problems of how to get through the skin of a slain animal, dismember it, and divide the meat.
The Acheulean industry
As the Pleistocene Epoch progressed, humans slowly developed the primitive chopper into a better instrument. About half a million years ago a superior implement finally appeared after nearly 2 million years of effort. The industry, or style, is known as the Acheulean, and the typical implement was the flint hand ax (sometimes called a fist hatchet). Throughout the ages the plump chopper and its bluntly angled crest had been streamlined by starting with a longer piece of rock and flaking the entire surface to produce an almond-shaped (amygdaloid) implement 20–25 cm (8–10 inches) long. This stone, much thinner than the chopper, was also sharper and more effective because the cutting edges were formed from the intersection of two curved and flaked surfaces (bifacial working).
This Acheulean hand ax was the product of evolution; certain of the intermediate stages, clearly leading to the typical and standardized form, have been identified as Chellean and Abbevillian. Despite the term ax, the tool was not hafted but was simply held in the hand. One end was tapered, the other rounded. The tapered end might be rather pointed or have a small straight edge. The tool was sharp for most of its periphery and seems to have been primarily a hunter’s knife but probably very useful, too, for other purposes, such as chopping, scraping, grubbing, and even piercing. Sharp, thin and symmetrical, light and elegant, it was quite different from the heavy chopper, with its rather blunt edge.
Another biface, the Acheulean cleaver, assumed prominence about 250,000 years later. A variant of the hand ax, it had a wide cutting edge across the end instead of a point and was better suited than the hand ax for hunting or hacking wood.
Neanderthals, excellent hunters and toolmakers, appeared on the scene at least 200,000 years ago, just ahead of the last glaciation but well within the Acheulean. Their tool kit was impressive for the wide variety of hand axes, borers, knives, and choppers it contained. The kit was novel for its scrapers and heavily serrated blades having a sawlike appearance, implements that were essential to the working of wood, bone, and horn into tools and weapons. The Neanderthals regularly used fire, and it is presumed that they could make it, although the direct evidence is missing. Fire was useful in tool manufacture, for charring the end of a stick not only helped shape the point by making it easier to scrape but also hardened it, as for a spear point. This fire hardening was probably the first human-manufactured modification of a natural property. Thoroughly wet wood, bent to shape and brought to dryness over the heat of a fire, would retain its bent form, a most useful property.
The Mousterian flake tools
The Mousterian and related flake industries followed the Acheulean. A refinement of the prepared-core technique, termed Levallois, was developed during the middle to upper Acheulean. In this method, a core was craftily trimmed in such a manner that a skillfully applied last blow would detach a large preshaped flake directly usable as an implement; the core was discarded. Such a flake tool, with one flat surface, is known as a unifacial tool because a single bevel forms the working edge. There are two principal kinds of flakes, points and scrapers. The former are roughly triangular, with two trimmed or sharp edges meeting in a point, the base or butt of the triangle being thick and blunt. The side scrapers have a sharp edge in the long direction of the flake, with an opposite, thicker butt section. The scraper could function as a knife, although it is speculated that it was used for working wood and skins, a supposition leading to the idea that skins were being used for clothing.
Late Paleolithic toolmaking
The fourth phase of Paleolithic toolmaking was introduced perhaps 40,000 years ago by the Aurignacian industry, a forerunner of the last and most brilliant achievements of the Old Stone Age. Extraordinary inventiveness was characteristic of the Aurignacian tradition and its several short-term successors. They can be lumped into a unit of development that spans the next 25,000 years.
Fully modern humans—whose first representative is the Cro-Magnon—emerged within this period, perhaps 35,000 years ago, during the time of the development and elaboration of rock technology, which, by providing a variety of specialized tools, mostly of the flake and blade types, at last brought materials other than rock into extensive use. It was also a time when the great plains in northern and eastern Europe carried such a heavy reindeer population, in addition to wild horses and mammoths, that it has been called the Reindeer Age. This produced a hunting economy providing food and great quantities of bone, horn, skin, sinews, and, while the mammoth lasted, ivory; with it grew new technologies exploiting the unique properties of materials hitherto unworkable because of their hardness. This technological diversification was made possible by new techniques and rock tools, whose specialization and complexity fit them to the fresh tasks. The most significant tool was the burin, or graver, a stout, narrow-bladed flint able to scrape narrow grooves in bone; two parallel grooves, for example, would allow a sliver of bone to be detached as stock for a needle, pin, awl, or other small object. Larger pieces of bone were worked into hooks with one or more barbs or points. Sections of antler were carved into splitting wedges to work out long pieces of bone to form the dartlike projectiles of the spear-thrower. Sandrock polishers were added to the tool kit to sharpen and shape tips, needles, and other articles.
A spectacular item that developed by the end of the Paleolithic was the spear-thrower, a hand-held stick, of wood or antler, notched at one end. Functioning as an extension of the arm, it added considerable kinetic energy, and therefore range, to a short spear tipped with flint or bone. The tipped projectile represented still another innovation, for it was the first hafted implement.
Hafting, or the fitting of a handle to a cutting edge, was a momentous and far-reaching invention of about 35,000 years ago. It was a critical step toward the creation of new tools and improved models of old ones. In its simplest form, the haft may have been no more than a grass or leaf bundle whose limited function was to protect the hand when a fractured rock was used as a knife. Mechanically, the handle became a force-transmitting intermediary between the source of the force and the toolhead. An extension of the arms, the handle provided an increased radius of swing. This moved the toolhead faster to give it more kinetic energy for a harder and more telling blow than the arms alone could provide. A man using a hand-held axhead could cut only small trees, whereas with a hafted ax he could fell a tree of almost any size.
The prepared-core technique that provided preshaped flakes was refined and extended to provide preshaped blades, long, slender pieces of flint of trapezoidal cross section, each corner having a straight cutting edge without the serrations of a chipped tool. This is known as the blade tool industry, a final complement to the core and flake tool technologies. Such blades made thin and splendid knives of great variety; many of these knives were backed; that is, the back of the blade was blunted for safer handling. Thin blades were further reduced to smaller pieces, often having a geometric form such as triangular, square, or trapezoidal, called microliths. These small bits of sharp flint were cemented (using resin) into a groove in a piece of wood to form a tool with a cutting edge longer than it was feasible to produce in a single piece of brittle flint; examples are a spear with a long cutting edge or the farmer’s sickle of later date.
The second major mechanical invention of the Upper Paleolithic was the bow, a device even more effective than the spear-thrower for increasing the distance between the hunter and the hunted. It is difficult to date precisely, for the only evidence of its use is found in cave paintings. Mere finds of rock points without bows prove nothing because such tips were used on the projectiles of spear-throwers. The earliest representations of the bow come from North Africa from 30,000 to 15,000 bce. Once the bow had been devised, it spread with astonishing rapidity, its effectiveness making it the weapon par excellence. When the bow was pulled, it stored the gradually expended energy of the archer’s muscles; this energy was suddenly released to give the projectile a “muzzle velocity” far higher than that possible from a spear-thrower and of superior accuracy. It was a principal weapon through the 15th century ce and was ousted then only by gunpowder.
