Scale of temperature the Swedish astronomer Anders Celsius (1701–1744), who developed a similar temperature scale two years before his death. The degree Celsius (°C) can refer to a specific temperature on the Celsius scale as well as a unit to indicate a temperature "interval "(a difference between two temperatures or an uncertainty). From 1744 until 1954, 0 °C was defined as the freezing point of water and 100 °C was defined as the boiling point of water, both at a pressure of one standard atmosphere. Although these defining correlations are commonly taught in schools today, by international agreement the unit "degree Celsius" and
Wedgwood scale thermometer to temperatures below 356 °C, which is too low for many industrial applications such as pottery, glass making and metallurgy. To solve this problem, the English potter Josiah Wedgwood proposed, in the 18th century, a method to measure temperatures in his kilns. His method and temperature scale were then widely adopted in science and technical applications. They were abandoned after the invention of accurate types of pyrometer, for example the pyrometer of John Frederic Daniell in 1830. A 0.5-inch-diameter cylinder made from pipe clay was dried at the temperature of boiling water. This would prepare it for heating in