Kettle

A kettle, sometimes called a tea kettle or teakettle, is a type of pot, typically metal, specialized for boiling water over a heat source, with a lid, spout and handle, or a small kitchen appliance of similar shape that functions in a self-contained manner. Kettles can be heated either by placing on a stove, or by their own internal electric heating element in the appliance versions.

History

The first kettles were used in ancient Mesopotamia for purposes other than cooking. Over time these artistically decorated earthenware containers became more frequently utilized in the kitchen. In China, kettles were typically made of iron and were placed directly over an open flame. Travelers used the kettles to boil fresh water to make it suitable for drinking.
The word kettle originates from Old Norse ketill "cauldron". The Old English spelling was ċetel with initial che-  like 'cherry', Middle English (and dialectal) was chetel, both come (together with German Kessel "cauldron") ultimately from Germanic *katilaz, that was borrowed from Latin catillus, diminutive form of catīnus "deep vessel for serving or cooking food", which in various contexts is translated as "bowl", "deep dish", or "funnel".
The development of tea kettles was in direct correlation with the evolution of the modern stove.
The electric kettle, could simply be plugged in instead of needing to be heated on a stove, was invented in 1922 by Arthur Leslie Large of Birmingham, England.
In the latter part of the 1800s, with the height of the industrial revolution, electric tea kettles were introduced as an alternative to stove top kettles. The first electric kettles had a warming chamber outside of the water source; but this was soon adapted in favor of an internal warming apparatus.
Modern tea kettles include a variety of technological advancements. Some electric kettles are cordless with illumination capabilities. Whistling kettles are equipped with lightweight dynamics and heat-resistant handles.

Electric kettles

Electric kettles are normally constructed of durable plastic or steel (with a plastic handle) and powered by mains electricity. In modern kettles the heating element is typically fully enclosed, with a power rating of 2 - 3 kW. In countries with 110V mains electricity, kettles may be less powerful to avoid drawing too much current and requiring a very thick supply wire.
In modern designs, once the water has reached boiling point, the kettle automatically deactivates, preventing the water from boiling away and damaging the heating element. A bimetallic strip thermostat is commonly used as the automatic shut-off mechanism. The thermostat is isolated from the water in the kettle and is instead heated by the steam created when the water boils, which is directed through a duct onto the bimetallic strip. This allows the thermostat to be coarsely calibrated, which in turn allows the kettle to function normally at a wide range of altitudes. A consequence of this design is that the kettle may fail to deactivate if the lid is left open, due to an insufficient amount of steam being ducted onto the bimetallic strip.
Jug kettles became popular in the late 20th century. They have a more upright design and are more economical to use, since small amounts of water (e.g. for one cup of tea) can be boiled while still keeping the element covered.
Electric kettles were introduced as means to boil water without the necessity of a stove top. In the United States an electric kettle may sometimes be referred to as a hot pot.