Anders Celsius (1701-1744), a Swedish astronomer, did not invent the thermometer nor temperature, but for his metereological observations he constructed his world famous Celsius thermometer, starting at the boiling point of water - 0 degrees Celsius and giving 100 degrees for the freezing point. In 1742 Celsius published a paper in the "Kungliga Swenska Wetenskaps Academiens Handlingar", the Annals of the Royal Swedish Academy of Science, entitled "Observations on two persistent degrees on a thermom eter". This paper is the origin of the Celsius temperature scale.
For a long time, the Celsius scale was called "centigrade." The Greek prefix "centi" means one-hundredth and each degree Celsius is one-hundredth of the way between the temperatures of freezing and boiling for water. After the death of Celsius in 1744 the scale was reversed to its present form. The Celsius temperature scale is part of the "metric system" of measurement (SI) and is used throughout the world, almost.