Thermometer
Developed during the 16th and 17th centuries, a thermometer is a device that measures temperature.
A thermometer has two important elements: the temperature sensor (e.g. the bulb on a mercury thermometer) in which some physical change occurs with temperature, plus some means of converting this physical change into a numerical value (e.g. the scale on a mercury thermometer).
In 1665 Christiaan Huygens suggested using the melting and boiling points of water as standards. In 1724 Daniel Gabriel Fahrenheit produced a temperature scale which now bears his name. In 1742 Anders Celsius proposed a scale with zero at the boiling point and 100 degrees at the melting point of water, though the scale which now bears his name has them the other way around.
A thermometer has two important elements: the temperature sensor (e.g. the bulb on a mercury thermometer) in which some physical change occurs with temperature, plus some means of converting this physical change into a numerical value (e.g. the scale on a mercury thermometer).
In 1665 Christiaan Huygens suggested using the melting and boiling points of water as standards. In 1724 Daniel Gabriel Fahrenheit produced a temperature scale which now bears his name. In 1742 Anders Celsius proposed a scale with zero at the boiling point and 100 degrees at the melting point of water, though the scale which now bears his name has them the other way around.