Celsius Celsius The Celsius scale, also known as the centigrade scale, is a temperature scale used by the International System of Units (SI). As an SI derived unit, it is used by all countries except the United States, the Bahamas, Belize, the Cayman Islands and Liberia. It is named after the Swedish astronomer Anders Celsius (1701–1744), who developed a similar temperature scale. The degree Celsius (°C) can refer to a specific temperature on the Celsius scale or a unit to indicate a difference between two temperatures or an uncertainty. Before being renamed to honor Anders Celsius in 1948, the unit was
Wedgwood scale of temperature. He also determined the melting points of three metals, namely copper (27 °W or ), silver (28 °W or ) and gold (32 °W or ). All these values are at least too high. Louis-Bernard Guyton de Morveau used his pyrometer to evaluate the temperature scale of Wedgwood and came to the conclusion that the starting point should be significantly lower, at instead of , and that the steps should be nearly halved from to no more than . However, even after this revision the Wedgwood measurements overestimated the melting points of elements. Wedgwood scale The Wedgwood scale