A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task, and proto-typically refers to solid hand-operated non-biological objects with a single broad purpose that lack multiple functions, unlike machines or computers. Although human beings are proportionally most active in using and making tools in the animal kingdom, as use of stone tools dates back hundreds of millennia, and also in using tools to make other tools, many animals have demonstrated tool use in both instances.
Early human tools, made of such materials as stone, bone, and wood, were used for the preparation of food, hunting, the manufacture of weapons, and the working of materials to produce clothing and useful artifacts and crafts such as pottery, along with the construction of housing, businesses, infrastructure, and transportation. The development of metalworking made additional types of tools possible. Harnessing energy sources, such as animal power, wind, or steam, allowed increasingly complex tools to produce an even larger range of items, with the Industrial Revolution marking an inflection point in the use of tools. The introduction of widespread automation in the 19th and 20th centuries allowed tools to operate with minimal human supervision, further increasing the productivity of human labor. By extension, concepts that support systematic or investigative thought are often referred to as "tools" or "toolkits".
Definition While a common-sense understanding of the meaning of tool is widespread, several formal definitions have been proposed.
In 1981, Benjamin Beck published a widely used definition of tool use. This has been modified to:Other, briefer definitions have been proposed:
History
Anthropologists believe that the use of tools was an important step in the evolution of humankind. Because tools are used extensively by both humans (Homo sapiens) and wild chimpanzees, it is widely assumed that the first routine use of tools took place prior to the divergence between the two ape species. These early tools, however, were likely made of perishable materials such as sticks, or consisted of unmodified stones that cannot be distinguished from other stones as tools.
Stone artifacts date back to about 2.5 million years ago. Also (paperback) However, a 2010 study suggests the hominin species Australopithecus afarensis ate meat by carving animal carcasses with stone implements. This finding pushes back the earliest known use of stone tools among hominins to about 3.4 million years ago. Finds of actual tools date back at least 2.6 million years in Ethiopia. One of the earliest distinguishable stone tool forms is the hand axe.
Up until recently, weapons found in digs were the only tools of early humans that were studied and given importance. Now, more tools are recognized as culturally and historically relevant. As well as hunting, other activities required tools such as preparing food, "...nutting, leatherworking, grain harvesting and woodworking..." Included in this group are "flake stone tools".
Tools are the most important items that the ancient humans used to climb to the top of the food chain; by inventing tools, they were able to accomplish tasks that human bodies could not, such as using a spear or bow to kill prey, since their teeth were not sharp enough to pierce many animals' skins. "Man the hunter" as the catalyst for Hominin change has been questioned. Based on marks on the bones at archaeological sites, it is now more evident that pre-humans were scavenging off of other predators' carcasses rather than killing their own food. Early humans progressively invented tools and techniques for trapping animals.
Timeline of ancient tool development Many tools were made in prehistory or in the early centuries of recorded history, but archaeological evidence can provide dates of development and use. Olduvai stone technology (Oldowan) 2.5 million years ago (scrapers; to butcher dead animals) Huts, 2 million years ago. Acheulean stone technology 1.6 million years ago (hand axe) Fire creation and manipulation, used since the Paleolithic, possibly by Homo erectus as early as 1.5 Million years ago Boats, 900,000 years ago. Cooking, 500,000 years ago. Javelins, 400,000 years ago. Glue, 200,000 years ago. Clothing possibly 170,000 years ago. Stone tools, used by Homo floresiensis, possibly 100,000 years ago. Harpoons, 90,000 years ago. Bow and arrows, 70,000–60,000 years ago. Sewing needles, 60,000 – 50,000 BC Flutes, 43,000 years ago. Fishing nets, 43,000 years ago. Ropes, 40,000 years ago. Ceramics Fishing hooks, . Domestication of animals, Sling (weapon) Microliths Brick used for construction in the Middle East Agriculture and Plough Wheel Gnomon Writing systems Copper Bronze Salt Chariot Iron Sundial Glass Catapult Cast iron Horseshoe Stirrup first few centuries AD
Several of the six classic simple machines (wheel and axle, lever, pulley, inclined plane, wedge, and screw) were invented in Mesopotamia. The wheel and axle mechanism first appeared with the potter's wheel, invented in what is now Iraq during the 5th millennium BC. This led to the invention of the wheeled vehicle in Mesopotamia during the early 4th millennium BC. The lever was used in the shadoof water-lifting device, the first crane machine, which appeared in Mesopotamia , and then in ancient Egyptian technology . The earliest evidence of pulleys date back to Mesopotamia in the early 2nd millennium BC.
The screw, the last of the simple machines to be invented, first appeared in Mesopotamia during the Neo-Assyrian period (911–609 BC). The Assyrian King Sennacherib (704–681 BC) claims to have invented automatic sluices and to have been the first to use water screw pumps, of up to 30 tons weight, which were cast using two-part clay molds rather than by the 'lost wax' process.S Dalley, The Mystery of the Hanging Gardens of Babylon, Oxford University Press(2013) The Jerwan Aqueduct ( is made with stone arches and lined with waterproof concrete.T Jacobsen and S Lloyd, Sennacherib's Aqueduct at Jerwan, Chicago University Press, (1935) The earliest evidence of water wheels and watermills date back to the ancient Near East in the 4th century BC,Terry S. Reynolds, Stronger than a Hundred Men: A History of the Vertical Water Wheel, JHU Press, 2002 , p. 14 specifically in the Persian Empire before 350 BC, in the regions of Mesopotamia (Iraq) and Persia (Iran). This pioneering use of water power constituted perhaps the first use of mechanical energy. The screwdriver for driving fastening screws was, however, not invented until the late 15th century.
Mechanical devices experienced a major expansion in their use in Ancient Greece and Ancient Rome with the systematic employment of new energy sources, especially waterwheels. Their use expanded through the Dark Ages with the addition of windmills.
Machine tools Machine tools occasioned a surge in producing new tools in the Industrial Revolution. Pre-industrial machinery was built by various craftersmillwrights built water and windmills, carpenters made wooden framing, and smiths and turners made metal parts. Wooden components had the disadvantage of changing dimensions with temperature and humidity, and the various joints tended to rack (work loose) over time. As the Industrial Revolution progressed, machines with metal parts and frames became more common.
Other important uses of metal parts were in firearms and threaded fasteners, such as machine screws, bolts, and nuts. There was also the need for precision in making parts. Precision would allow better working machinery, interchangeability of parts, and standardization of threaded fasteners. The demand for metal parts led to the development of several machine tools. They have their origins in the tools developed in the 18th century by makers of clocks and watches and scientific instrument makers to enable them to batch-produce small mechanisms. Before the advent of machine tools, metal was worked manually using the basic hand tools of hammers, files, scrapers, saws, and chisels. Consequently, the use of metal machine parts was kept to a minimum. Hand methods of production were very laborious and costly and precision was difficult to achieve. Reprinted by McGraw-Hill, New York and London, 1926 (); and by Lindsay Publications, Inc., Bradley, Illinois, (). With their inherent precision, machine tools enabled the economical production of interchangeable parts.
Examples of machine tools include:
Broaching machine Drill press Gear shaper Hobbing machine Hone Lathe Screw machines Milling machine Shear (sheet metal) Shaper Bandsaw Planer Stewart platform mills Grinding machines Advocates of nanotechnology expect a similar surge as tools become microscopic in size.
Types
One can classify tools according to their basic functions: Cutting and edge tools, such as the knife, sickle, scythe, hatchet, and axe, are wedge-shaped implements that produce a shearing force along a narrow face. Ideally, the edge of the tool needs to be harder than the material being cut or the blade will become dulled with repeated use. But even resilient tools will require periodic sharpening, which is the process of removing deformation wear from the edge. Other examples of cutting tools include gouges and drill bits. Moving tools move large and tiny items. Many are levers which give the user a mechanical advantage. Examples of force-concentrating tools include the hammer which moves a nail or the maul which moves a stake. These operate by applying physical compression to a surface. In the case of the screwdriver, the force is rotational and called torque. By contrast, an anvil concentrates force on an object being hammered by preventing it from moving away when struck. Writing implements deliver a fluid to a surface via compression to activate the ink cartridge. Grabbing and twisting nuts and bolts with pliers, a glove, a wrench, etc. likewise move items by applying torque (rotational force). Tools that enact chemical changes, including temperature and ignition, such as lighters and blowtorches. Guiding, measuring and perception tools include the ruler, glasses, square, sensors, straightedge, theodolite, microscope, monitor, clock, phone, printer Shaping tools, such as molds, jigs, trowels. Fastening tools, such as welders, soldering irons, rivet guns, nail guns, or glue guns. Information and data manipulation tools, such as computers, IDE, spreadsheets
Some tools may be combinations of other tools. An alarm-clock is for example a combination of a measuring tool (the clock) and a perception tool (the alarm). This enables the alarm-clock to be a tool that falls outside of all the categories mentioned above.
There is some debate on whether to consider protective gear items as tools, because they do not directly help perform work, just protect the worker like ordinary clothing. They do meet the general definition of tools and in many cases are necessary for the completion of the work. Personal protective equipment includes such items as gloves, safety glasses, ear defenders and biohazard suits.
Function Tool substitution