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86-584: An oven is a tool that is used to expose materials to a hot environment. Ovens contain a hollow chamber and provide a means of heating the chamber in a controlled way. In use since antiquity , they have been used to accomplish a wide variety of tasks requiring controlled heating. Because they are used for a variety of purposes, there are many different types of ovens . These types differ depending on their intended purpose and based upon how they generate heat. Ovens are often used for cooking , usually baking , sometimes broiling ; they can be used to heat food to

172-414: A fuel , such as wood , coal , or natural gas , while many employ electricity . Microwave ovens heat materials by exposing them to microwave radiation , while electric ovens and electric furnaces heat materials using resistive heating . Some ovens use forced convection , the movement of gases inside the heating chamber, to enhance the heating process, or, in some cases, to change the properties of

258-580: A hearth used for heating and cooking. Ovens were used by cultures who lived in the Indus Valley and in pre-dynastic Egypt. By 3200 BC, each mud-brick house had an oven in settlements across the Indus Valley. Ovens were used to cook food and to make bricks. Pre-dynastic civilizations in Egypt used kilns around 5000–4000 BC to make pottery. Tandır ovens used to bake unleavened flatbread were common in Anatolia during

344-431: A thermistor to monitor the temperature close to the pan, and cut off the gas supply if the heat is too high. Fire loss statistics for Japanese gas stoves showed a reduction in house fires caused by gas stoves in the years following 2008, when the safety devices were mandated. The U.S. Department of Energy (DOE) ran tests in 2014 of cooktop energy transfer efficiency, simulating cooking while testing what percentage of

430-500: A "Birth Choice tool": The tool encourages women to consider out-of-hospital settings where appropriate, and the idea of a "toolkit" is used by the International Labour Organization to describe a set of processes applicable to improving global labour relations . A telephone is a communication tool that interfaces between two people engaged in conversation at one level. It also interfaces between each user and

516-492: 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

602-553: A bill in the Republican-controlled House of Representatives narrowly failed as a dozen Republican legislators voted against the bill due to a disagreement with the Republican leadership on unrelated issues. Gas stoves are often run on natural gas. The extraction and consumption of natural gas is a major and growing contributor to climate change . Both the gas itself (specifically methane ) and carbon dioxide , which

688-469: A cheap tool could be used to occupy the place of a missing mechanical part. A window roller in a car could be replaced with pliers . A transmission shifter or ignition switch would be able to be replaced with a screwdriver. Again, these would be considered tools that are being used for their unintended purposes, substitution as makeshift. Tools such as a rotary tool would be considered the substitution "by-design", or "multi-purpose". This class of tools allows

774-660: A commercial success in England. By that stage a large and reliable network for gas pipeline transport had spread over much of the country, making gas relatively cheap and efficient for domestic use. Gas stoves only became widespread on the European Continent and in the United States in the early 20th century. By the early 1920s, gas stoves with enameled porcelain finishes for easier cleaning had become widely available, along with heavy use of insulation for fuel-efficiency. In

860-628: A cooking tool was discovered by Percy Spencer in 1946, and with help from engineers, the microwave oven was patented. The microwave oven uses microwave radiation to excite water molecules in food, causing friction and thus producing heat. Some ovens can perform in multiple ways, sometimes at once. Combination ovens may be able to microwave and conventional heating such as baking or grilling simultaneously. Ovens are used as kitchen appliances for roasting and heating. Foods normally cooked in this manner include meat , casseroles and baked goods such as bread , cake and other desserts . In modern times,

946-450: A cooktop's energy is transferred to a test block. Gas had an efficiency of 43.9%, with ±0.5% repeatability in the measurement. This level of efficiency is only possible if the pan is big enough for the burner. Japanese gas flames are angled upwards towards the pot to increase efficiency. The efficiency of gas appliances can be raised by using special pots with heatsink -like fins. Jetboil manufactures pots for portable stoves that use

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1032-763: A corrugated ribbon to increase efficiency. Carbon monoxide , formaldehyde , benzene and nitrogen dioxide from gas stoves contribute to indoor air pollution, causing around 60 thousand early deaths each year (40 thousand in Europe and 19 thousand in the United States). Nitrogen dioxide can exacerbate respiratory illnesses, such as asthma or chronic obstructive pulmonary disease . Studies have been performed correlating childhood asthma and gas stoves. A 1999–2004 study published in The Lancet Respiratory Medicine found "no evidence of an association between

1118-401: A desired temperature . Ovens are also used in the manufacturing of ceramics and pottery ; these ovens are sometimes referred to as kilns . Metallurgical furnaces are ovens used in the manufacturing of metals , while glass furnaces are ovens used to produce glass . There are many methods by which different types of ovens produce heat. Some ovens heat materials using the combustion of

1204-611: A diverse array of objects and materials, many of which are specifically chosen by certain birds for their unique qualities. Woodpecker finches insert twigs into trees in order to catch or impale larvae. Parrots may use tools to wedge nuts so that they can crack open the outer shell of nuts without launching away the inner contents. Some birds take advantage of human activity, such as carrion crows in Japan, which drop nuts in front of cars to crack them open. Several species of fish use tools to hunt and crack open shellfish, extract food that

1290-428: A known carcinogen , accumulated in homes to unhealthy levels when natural gas or propane stoves were used, especially when vent hoods were not used. The Stanford researchers determined benzene is emitted from the cooking gas, not the food being cooked. Benzene exposure causes both cancer and noncancerous health effects. Shorter-term benzene exposure suppresses blood cell production, and chronic benzene exposure increases

1376-768: A large pot of water quickly, sautéing and searing , while the low output burners are good for simmering . Mean benzene emissions from gas and propane burners on high and ovens set to 350 °F ranged from 2.8 to 6.5 μg min–1, 10 to 25 times higher than emissions from electric coil and radiant alternatives. Some high-end cooktop models provide higher range of heat and heavy-duty burners that can go up to 6 kilowatts (20,000 BTU/h) or even more. These may be desired for preparing large quantities or special types of food and enable certain advanced cooking techniques. However, these burners produce greater emissions and necessitate better ventilation for safe operation. Higher capacity burners may not benefit every potential user or dish. In

1462-532: A localized or isolated manner within certain unique primate cultures , being transmitted and practiced among socially connected primates through cultural learning . Many famous researchers, such as Charles Darwin in his book The Descent of Man , mentioned tool-use in monkeys (such as baboons ). Among other mammals , both wild and captive elephants are known to create tools using their trunks and feet, mainly for swatting flies, scratching, plugging up waterholes that they have dug (to close them up again so

1548-682: 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 occasioned a surge in producing new tools in the Industrial Revolution . Pre-industrial machinery was built by various craftsmen— millwrights built water and windmills, carpenters made wooden framing, and smiths and turners made metal parts. Wooden components had

1634-407: A match. If one accidentally left the gas on, gas would fill the oven and eventually the room. A small spark, such as an arc from a light switch being turned on, could ignite the gas, triggering a violent explosion. To prevent these types of accidents, oven manufacturers developed and installed a safety valve called a flame failure device for gas hobs (cooktops) and ovens. The safety valve depends on

1720-467: A particular task. Although many animals use simple tools , only human beings, whose use of stone tools dates back hundreds of millennia, have been observed using tools to make other tools. 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

1806-419: A position typically labeled "LITE" or by pressing the 'ignition' button. Once the burner lights, the knob is turned further to modulate the flame size. Auto reignition is an elegant refinement: the user need not know or understand the wait-then-turn sequence. They simply turn the burner knob to the desired flame size and the sparking is turned off automatically when the flame lights. Auto reignition also provides

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1892-415: A safety feature: the flame will be automatically reignited if the flame goes out while the gas is still on—for example by a gust of wind. If the power fails, surface burners must be manually match-lit. Electric ignition for ovens uses a "hot surface" or "glow bar" ignitor. Basically it is a heating element that heats up to gas's ignition temperature. A sensor detects when the glow bar is hot enough and opens

1978-454: A similar carbon footprint to other fossil fuels overall. The first gas stove was developed in 1802 by Zachäus Winzler ( de ), but this along with other attempts remained isolated experiments. James Sharp patented a gas stove in Northampton, England in 1826 and opened a gas stove factory in 1836. His invention was marketed by the firm Smith & Philips from 1828. An important figure in

2064-576: A target goal. Anthropologists believe that the use of tools was an important step in the evolution of mankind . 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. However,

2150-416: A thermocouple that sends a signal to the valve to stay open. Although most modern gas stoves have electronic ignition, many households have gas cooking ranges and ovens that need to be lit with a flame. Electric ignition stoves use electric sparks to ignite the surface burners. This is the "clicking sound" audible just before the burner actually lights. The sparks are initiated by turning the gas burner knob to

2236-449: A wide variety of operating modes and special features including the use of a temperature probe to automatically shut the oven off when the food is completely cooked to the desired degree. Toaster ovens are essentially small-scale ovens and can be used to cook foods other than just toasting. A frontal door is opened, horizontally-oriented bread slices (or other food items) are placed on a rack that has heat elements above and below it, and

2322-409: A widely used definition of tool use. This has been modified to: The external employment of an unattached or manipulable attached environmental object to alter more efficiently the form, position, or condition of another object, another organism, or the user itself, when the user holds and directly manipulates the tool during or prior to use and is responsible for the proper and effective orientation of

2408-455: Is "makeshift" when human ingenuity comes into play and a tool is used for an unintended purpose, such as using a long screwdriver to separate a cars control arm from a ball joint, instead of using a tuning fork. In many cases, the designed secondary functions of tools are not widely known. For example, many wood-cutting hand saws integrate a square by incorporating a specially-shaped handle, that allows 90° and 45° angles to be marked by aligning

2494-518: Is a motto of some importance for workers who cannot practically carry every specialized tool to the location of every work task, such as a carpenter who does not necessarily work in a shop all day and needs to do jobs in a customer's house. Tool substitution may be divided broadly into two classes: substitution "by-design", or "multi-purpose", and substitution as makeshift. Substitution "by-design" would be tools that are designed specifically to accomplish multiple tasks using only that one tool. Substitution

2580-450: 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

2666-483: Is made with stone arches and lined with waterproof concrete. The earliest evidence of water wheels and watermills date back to the ancient Near East in the 4th century BC, 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 . Mechanical devices experienced

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2752-545: Is out of reach, or clear an area for nesting. Among cephalopods (and perhaps uniquely or to an extent unobserved among invertebrates ), octopuses are known to use tools relatively frequently, such as gathering coconut shells to create a shelter or using rocks to create barriers. By extension, concepts which support systematic or investigative thought are often referred to as "tools", for example Vanessa Dye refers to "tools of reflection" and "tools to help sharpen your professional practice" for trainee teachers, illustrating

2838-496: Is released when natural gas is burned, are greenhouse gases . In 2022, a research group investigated leakage in 53 homes in California and estimated the methane emissions from gas stoves in the United States were equivalent over a 20-year period to the greenhouse gas emissions of 500,000 cars. About 80% of methane emissions occur when stoves are turned off, as the result of leaks in gas lines and fittings. Some places, such as

2924-545: Is still central to rural food culture in this part of the world, reflected by the local folklore, in which a young man and woman sharing fresh tandır bread is a symbol of young love. However, the culture of traditional bread baking is changing with younger generations, especially with those who reside in towns and prefer modern conveniences. During the Middle Ages, instead of earth and ceramic ovens, Europeans used fireplaces in conjunction with large cauldrons. These were similar to

3010-525: The AGA cooker ) may not have any controls at all; the ovens simply run continuously at various temperatures. More conventional ovens have a simple thermostat which turns the oven on and off and selects the temperature at which it will operate. Set to the highest setting, this may also enable the broiler element. A timer may allow the oven to be turned on and off automatically at pre-set times. More sophisticated ovens may have complex, computer -based controls allowing

3096-517: The Dutch oven . After the Middle Ages, ovens underwent many changes over time from wood, iron, coal, gas, and even electric. Each design had its own motivation and purpose. The wood-burning stoves saw improvement through the addition of fire chambers that allowed better containment and release of smoke. Another recognizable oven would be the cast-iron stove. These were first used around the early 1700s, when they themselves underwent several variations including

3182-640: The Swiss Army knife represents one of the earliest examples. Other tools have a primary purpose but also incorporate other functionality – for example, lineman's pliers incorporate a gripper and cutter and are often used as a hammer; and some hand saws incorporate a square in the right-angle between the blade's dull edge and the saw's handle. This would also be the category of "multi-purpose" tools, since they are also multiple tools in one (multi-use and multi-purpose can be used interchangeably – compare hand axe ). These types of tools were specifically made to catch

3268-440: The cooktop . The flame is between the front and back burners. When the stove is turned on, this flame lights the gas flowing out of the burners. The advantage of the standing pilot system is that it is simple and completely independent of any outside power source. A minor drawback is that the flames continuously consume fuel even when the stove is not in use. Early gas ovens did not have a pilot. One had to light these manually with

3354-435: The methane emissions from gas stoves in the United States were equivalent to the greenhouse gas emissions of 500,000 cars. About 80% of methane emissions were found to occur even when stoves are turned off, as the result of tiny leaks in gas lines and fittings. Although methane contains less carbon than other fuels, gas venting and unintended fugitive emissions throughout the supply chain results in natural gas having

3440-480: The 1960s the American Gas Association ran an advertising campaign to promote gas stoves while also downplaying science showing their health risks, mirroring the tobacco industry playbook of creating uncertainty . Gas stoves today use two basic types of ignition sources, standing pilot and electric. A stove with a standing pilot has a small, continuously burning gas flame (called a pilot light ) under

3526-467: 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". While a common-sense understanding of the meaning of tool is widespread, several formal definitions have been proposed. In 1981, Benjamin Beck published

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3612-664: The Seljuk and Ottoman eras and have been found at archaeological sites distributed across the Middle East. The word tandır comes from the Akkadian tinuru , which becomes tanur in Hebrew and Arabic, and tandır in Turkish. Of the hundreds of bread varieties known from cuneiform sources, unleavened tinuru bread was made by adhering bread to the side walls of a heated cylindrical oven. This type of bread

3698-483: The Stewart Oberlin iron stove that was smaller and had its own chimney. In the early part of the 19th century, the coal oven was developed. It was cylindrical in shape and made of heavy cast iron. The gas oven saw its first use as early as the beginning of the 19th century as well. Gas stoves became very common household ovens once gas lines were available to most houses and neighborhoods. James Sharp patented one of

3784-719: The United States, one in eight cases of asthma in children are due to pollution from gas stoves. The asthma risk caused by gas stove exposure is similar in magnitude to that caused by secondhand smoke from tobacco. Stoves can cause levels of nitrogen dioxide that can exceed outdoor safety standards. A 2020 RMI report found pollution from gas stoves causes exacerbation of asthma symptoms in children. People interact more directly with their stove than with other gas appliances, increasing potential exposure to any natural gas constituents and compounds formed during combustion, including formaldehyde ( CH 2 O ) carbon monoxide ( CO ), and nitrogen oxides (NOx). Among all gas appliances,

3870-449: The appropriate part of the handle with an edge, and scribing along the back edge of the saw. The latter is illustrated by the saying "All tools can be used as hammers". Nearly all tools can be used to function as a hammer, even though few tools are intentionally designed for it and even fewer work as well as the original. Tools are often used to substitute for many mechanical apparatuses, especially in older mechanical devices. In many cases

3956-415: The automatic-toasting settings, toaster ovens typically have settings and temperature controls to allow use of the appliance as a small oven. Extra features on toaster ovens can include: Outside the culinary world, ovens are used for a number of purposes: Tool A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish

4042-540: The communication network at another level. It is in the domain of media and communications technology that a counter-intuitive aspect of our relationships with our tools first began to gain popular recognition. John M. Culkin famously said, "We shape our tools and thereafter our tools shape us". One set of scholars expanded on this to say: "Humans create inspiring and empowering technologies but also are influenced, augmented, manipulated, and even imprisoned by technology". Gas stove Gas stoves became more common when

4128-409: The completion of the work. Personal protective equipment includes such items as gloves , safety glasses , ear defenders and biohazard suits. Often, by design or coincidence, a tool may share key functional attributes with one or more other tools. In this case, some tools can substitute for other tools, either as a makeshift solution or as a matter of practical efficiency. "One tool does it all"

4214-455: The connection between physical and conceptual tools by quoting the French scientist Claude Bernaud : we must change [our ideas] when they have served their purpose, as we change a blunt lancet that we have used long enough. Similarly, a decision-making process "developed to help women and their partners make confident and informed decisions when planning where to give birth" is described as

4300-438: 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

4386-548: The cooking process. Ovens may also have two separate oven bays which allows cooking of two different dishes at the same time. Many gas stoves come with at least few modern programmable controls to make the handling easier. LCD displays and some other complex cooking routines are some of the standard features present in most of the basic and high-end manufacturing models. Some of the other programmable controls include precise pre-heating, automatic pizza, cook timers and others. Modern gas stove ranges are safer than older models. Two of

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4472-549: The definition of what constitutes a tool and therefore which behaviours can be considered true examples of tool use. Observation has confirmed that a number of species can use tools including monkeys , apes , elephants , several birds, and sea otters . Now the unique relationship of humans with tools is considered to be that we are the only species that uses tools to make other tools. Primates are well known for using tools for hunting or gathering food and water, cover for rain, and self-defense. Chimpanzees have often been

4558-407: 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

4644-627: 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

4730-547: The door is closed. The controls are set and actuated to toast the bread to the desired doneness, whereupon the heat elements are switched off. In most cases, the door must be opened manually, though there are also toaster ovens with doors that open automatically. Because the bread is horizontal, a toaster oven can be used to cook toast with toppings, like garlic bread , melt sandwiches , or toasted cheese . Toaster ovens are generally slower to make toast than pop-up toasters, taking 4–6 minutes as compared to 2–3 minutes. In addition to

4816-615: The early acceptance of this new technology, was Alexis Soyer , the renowned chef at the Reform Club in London. From 1841, he converted his kitchen to consume piped gas, arguing that gas was cheaper overall because the supply could be turned off when the stove was not in use. A gas stove was shown at the Great Exhibition in London in 1851, but it was only in the 1880s that the technology became

4902-467: The early centuries of recorded history, but archaeological evidence can provide dates of development and use. 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

4988-444: The eye of many different craftsman who traveled to do their work. To these workers these types of tools were revolutionary because they were one tool or one device that could do several different things. With this new revolution of tools, the traveling craftsman would not have to carry so many tools with them to job sites, in that their space would be limited to the vehicle or to the beast of burden they were driving. Multi-use tools solve

5074-487: The first gas stoves in 1826. Other improvements to the gas stove included the AGA cooker , invented in 1922 by Gustaf Dalén . The first electric ovens were invented in the very late 19th century; however, like many electrical inventions destined for commercial use, mass ownership of electrical ovens could not be a reality until a better and more efficient use of electricity was available. Over time, ovens have become more high-tech in terms of cooking strategy. The microwave as

5160-476: The front along with burner controls. Freestanding gas range cooktops have solid slides and controls placed behind the cooktop. Many stoves have integrated ovens. Modern ovens often include a convection fan inside the oven to provide even air circulation and let the food cook evenly. Some modern ovens come with temperature sensors which allows close control of baking, automatically shut off after reaching certain temperature, or hold on to particular temperature through

5246-402: The gas consumption rather than heat absorbed by pans. Often, a gas stove will have burners with different heat output ratings. For example, a gas cooktop may have a high output burner, often in the range 3 to 6 kilowatts (10,000 to 20,000 BTU/h), and a mixture of medium output burners, 1.5 to 3 kW, and low output burners, 1 kW or less. The high output burner is suitable for boiling

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5332-408: The gas valve. Also stoves with electric ignition must be connected with gas protection mechanisms such as gas control breaker. Because of this many manufacturers supply stoves without electricity plug. One of the important properties of a gas stove is the heat emitted by the burners. Burner heat is typically specified in terms of kilowatts or British Thermal Units per hour and is directly based on

5418-488: The gas without igniting it could lead to an explosion. To prevent these types of accidents, oven manufacturers developed and installed a safety valve called a flame failure device for gas hobs (cooktops) and ovens. Most modern gas stoves have electronic ignition, automatic timers for the oven and extractor hoods to remove fumes. Gas stoves are an indoor common fossil-fuel appliance that contribute significant levels of indoor air pollution , but good ventilation reduces

5504-490: The health risk. They also expose users to pollutants, such as nitrogen dioxide , which can trigger respiratory diseases, and have shown an increase in the rates of asthma in children. In June 2023, Stanford researchers found combustion from gas stoves can raise indoor levels of benzene , a potent carcinogen linked to a higher risk of blood cell cancers, to more than that found in secondhand tobacco smoke . Gas stoves also release methane. Research in 2022 estimated that

5590-461: 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 c.  3000 BC , and then in ancient Egyptian technology c.  2000 BC . The earliest evidence of pulleys date back to Mesopotamia in the early 2nd millennium BC. The screw ,

5676-435: The last few years, appliance manufacturers have been making innovative changes to the design and layout of gas stoves. Most of the modern cooktops have come with lattice structure which usually covers the complete range of the top, enabling sliding of cookware from one burner to another without lifting the containers over the gaps of cooktop. Some modern gas stoves also have central fifth burner or an integrated griddle in between

5762-484: 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. The Jerwan Aqueduct ( c.  688 BC)

5848-463: The major safety concerns with gas stoves are child-safe controls and accidental ignition. Some gas cooktops have knobs which can be accidentally switched on even with a gentle bump. Gas stoves are at risk of overheating when frying oil, raising the oil temperature to the auto-ignition point and creating an oil fire on the stove. Japan, South Korea and China have regulated the addition of electronic safety devices to prevent pan overheating. The devices use

5934-598: The material being heated, such as in the Bessemer method of steel production. The earliest ovens were found in Central Europe and date back to 29,000 BC. They were roasting and boiling pits inside yurts used to cook mammoth . In Ukraine from 20,000 BC they used pits with hot coals covered in ashes. Food was wrapped in leaves and set on top, then covered with earth. In camps found in Mezhirich , each mammoth bone house had

6020-480: The object of study in regard to their usage of tools, most famously by Jane Goodall ; these animals are closely related to humans. Wild tool-use in other primates, especially among apes and monkeys , is considered relatively common, though its full extent remains poorly documented, as many primates in the wild are mainly only observed distantly or briefly when in their natural environments and living without human influence. Some novel tool-use by primates may arise in

6106-412: The only tools of "early man" 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

6192-445: The outer burners. The size of a kitchen gas stove usually ranges from 50 to 150 centimetres (20 to 60 in). Almost all the manufacturers have been developing several range of options in size range. Combination of range and oven are also available which usually come in two styles: slide in and freestanding. Usually, there isn't much of a style difference in between them. Slide-in come with lips on their either side and controls over

6278-458: The oven from below. This is commonly used for baking and roasting. The oven may also be able to heat from the top to provide broiling (US) or grilling (UK/Commonwealth). A fan-assisted oven that uses a small fan to circulate the air in the cooking chamber, can be used. Both are also known as convection ovens . An oven may also provide an integrated rotisserie . Ovens also vary in the way that they are controlled. The simplest ovens (for example,

6364-451: The oven is used to cook and heat food in many households around the globe. Modern ovens are typically fueled by either natural gas or electricity , with bottle gas models available but not common. When an oven is contained in a complete stove, the fuel used for the oven may be the same as or different from the fuel used for the burners on top of the stove. Ovens usually can use a variety of methods to cook. The most common may be to heat

6450-430: The oven was integrated into the base and the size was reduced to better fit in with the rest of the kitchen furniture. By the 1910s, producers started to enamel their gas stoves for easier cleaning. Ignition of the gas was originally by match and this was followed by the more convenient pilot light . This had the disadvantage of continually consuming gas. The oven still needed to be lit by match and accidentally turning on

6536-427: The problem of having to deal with many different tools. Tool use by animals is a phenomenon in which an animal uses any kind of tool in order to achieve a goal such as acquiring food and water, grooming , defense, communication , recreation or construction . Originally thought to be a skill possessed only by humans , some tool use requires a sophisticated level of cognition. There is considerable discussion about

6622-427: The rear burners than the front burners. California requires gas stoves to have higher levels of ventilation than electric stoves due to the nitrogen dioxide risk. Range hoods can be run for 15 minutes after cooking to reduce pollution. The U.S. Consumer Product Safety Commission is investigating reducing the health effects of gas stoves, including emissions and ventilation standards. A 2023 study found benzene ,

6708-569: The risk of leukemias and lymphomas . A 2002 study of pipelines in Boston found that natural gas contains non-methane impurities including heptane , hexane , cyclohexane , benzene and toluene . After health concerns about gas stoves became more prominent in the 2020s and American localities regulated additions of gas stoves to new buildings, the Republican Party in the United States pushed legislative bills to "save gas stoves". In June 2023,

6794-549: The shells of prey, as well as for scratching. Corvids (such as crows , ravens and rooks ) are well known for their large brains (among birds ) and tool use. New Caledonian crows are among the only animals that create their own tools. They mainly manufacture probes out of twigs and wood (and sometimes metal wire) to catch or impale larvae . Tool use in some birds may be best exemplified in nest intricacy. Tailorbirds manufacture 'pouches' to make their nests in. Some birds, such as weaver birds , build complex nests utilizing

6880-496: The stove is unique in that the byproducts of combustion are emitted directly into home air with no requirement for venting the exhaust outdoors. Cooking, especially high heat frying, releases smoke (measured as fine particulate matter ), acrolein and polycyclic aromatic hydrocarbons . Mitigating indoor particulate pollution can involve running a range hood, opening a kitchen window, and running an air purifier . Range hoods are more effective at capturing and removing pollution on

6966-452: The tool. Other, briefer definitions have been proposed: An object carried or maintained for future use. The use of physical objects other than the animal's own body or appendages as a means to extend the physical influence realized by the animal. An object that has been modified to fit a purpose ... [or] An inanimate object that one uses or modifies in some way to cause a change in the environment, thereby facilitating one's achievement of

7052-530: 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. Many tools were made in prehistory or in

7138-479: The use of gas as a cooking fuel and either asthma symptoms or asthma diagnosis". A 2013 meta-analysis concluded that gas cooking increases the risk of asthma in children. A 2020 Lancet systematic review surveyed 31 studies on gas cooking or heating, finding a pooled risk ratio of 1.17 for asthma. One study found that in households with gas stoves those that report using ventilation had lower rates of asthma than those that did not. A 2023 meta-analysis estimated that in

7224-402: The use of one tool that has at least two different capabilities. "Multi-purpose" tools are basically multiple tools in one device/tool. Tools such as this are often power tools that come with many different attachments like a rotary tool does, so one could say that a power drill is a "multi-purpose" tool. A multi-tool is a hand tool that incorporates several tools into a single, portable device;

7310-519: The water does not evaporate), and reaching food that is out of reach. Many other social mammals particularly have been observed engaging in tool-use. A group of dolphins in Shark Bay uses sea sponges to protect their beaks while foraging. Sea otters will use rocks or other hard objects to dislodge food (such as abalone ) and break open shellfish . Many or most mammals of the order Carnivora have been observed using tools, often to trap or break open

7396-491: Was kept to a minimum. Hand methods of production were very laborious and costly and precision was difficult to achieve. With their inherent precision, machine tools enabled the economical production of interchangeable parts . Examples of machine tools include: Advocates of nanotechnology expect a similar surge as tools become microscopic in size. One can classify tools according to their basic functions: Some tools may be combinations of other tools. An alarm-clock

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