An electric stove or electric range is a stove with an integrated electrical heating device to cook and bake. Electric stoves became popular as replacements for solid-fuel (wood or coal) stoves which required more labor to operate and maintain. Some modern stoves come in a unit with built-in extractor hoods. The stove's one or more "burners" (heating elements) may be controlled by a rotary switch with a finite number of positions (which may be marked out by numbers such as 1 to 10, or by settings such as Low, Medium and High), each of which engages a different combination of resistances and hence a different heating power; or may have an "infinite switch" that allows constant variability between minimum and maximum heat settings. Some stove burners and controls incorporate thermostats. History Early patents On September 20, 1859, George B. Simpson was awarded US patent #25532 for an 'electro-heater' surface heated by a platinum-wire coil powered by batteries. In his words, useful to "warm rooms, boil water, cook victuals...". Canadian inventor Thomas Ahearn filed patent #39916 in 1892 for an "Electric Oven," a device he probably employed in preparing a meal for an Ottawa hotel that year. Ahearn and Warren Y. Soper were owners of Ottawa's Chaudiere Electric Light and Power Company. The electric stove was showcased at the Chicago World's Fair in 1893, where an electrified model kitchen was shown. Unlike the gas stove, the electrical stove was slow to catch on, partly due to the unfamiliar technology, and the need for cities and towns to be electrified. In 1897, William Hadaway was granted US patent # 574537 for an "Automatically Controlled Electric Oven". Kalgoorlie Stove In November 1905, David Curle Smith, the Municipal Electrical Engineer of Kalgoorlie, Western Australia, applied for a patent (Aust Patent No 4699/05) for a device that adopted (following the design of gas stoves) what later became the configuration for most electric stoves: an oven surmounted by a hotplate with a grill tray between them. Curle Smith's stove did not have a thermostat; heat was controlled by the number of the appliance's nine elements that were switched on. After the patent was granted in 1906, manufacturing of Curle Smith's design commenced in October that year. The entire production run was acquired by the electricity supply department of Kalgoorlie Municipality, which hired out the stoves to residents. About 50 appliances were produced before cost overruns became