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
Anders Henrik Bull Anders Henrik Bull Anders Henrik Bull (25 January 1875 – after 1909) was a Norwegian electrical engineer. He was born in Minneapolis as the son of ophthalmologist Ole Bornemann Bull (1842–1916) and his first wife Marie Cathrine Lund (1843–1884). The family moved to Norway in 1876. He took his engineering education in Kristiania and Hannover. He returned to Norway from Hannover in 1901, and became noted in the engineering community for his pioneering work on wireless telegraphy. He also worked for Norsk Hydro, as a consultant to Kristian Birkeland, from 1906 to 1909, in that company's formative phase. He married