Anders Celsius magnitude (a measure of brightness) of certain stars. This was the first attempt to measure the intensity of starlight with a tool other than the human eye. He made observations of eclipses and various astronomical objects and published catalogues of carefully determined magnitudes for some 300 stars using his own photometric system (mean error=0.4 mag). Celsius was the first to perform and publish careful experiments aiming at the definition of an international temperature scale on scientific grounds. In his Swedish paper "Observations of two persistent degrees on a thermometer" he reports on experiments to check that the freezing point is
Introduction to the metric system volt and farad in honour of Georg Ohm, Alessandro Volta and Michael Faraday respectively. This proposal had the support of William Thomson (Lord Kelvin) who had been instrumental in forming the Committee of Electrical Standards of the British Association for the Advancement of Science. The use of scientists' names for such units was subsequently extended to other units, including the watt named after James Watt and the degree Celsius named after Anders Celsius. Historically, individual units evolved which were based on the size and context of what was being measured. These units could avoid the need to use large numbers