The Newton scale is a temperature scale devised by Isaac Newton in 1701. He called his device a "thermometer", but he did not use the term "temperature", speaking of "degrees of heat" (gradus caloris) instead. Newton's publication represents the first attempt to introduce an objective way of measuring (what would come to be called) temperature (alongside the Rømer scale published at nearly the same time). Newton likely developed his scale for practical use rather than for a theoretical interest in thermodynamics; he had been appointed Warden of the Mint in 1695, and Master of the Mint in 1699, and his interest in the boiling points of metals are likely inspired by his duties in connection with the Royal Mint.
Newton used linseed oil as thermometric material and measured its change of volume against his reference points. He set as 0 on his scale "the heat of air in winter at which water begins to freeze" (Calor aeris hyberni ubi aqua incipit gelu rigescere), reminiscent of the standard of the modern Celsius scale (i.e. 0 °N = 0 °C), but he has no single second reference point; he does give the "heat at which water begins to boil" as 33, but this is not a defining reference; the values for body temperature and the boiling point of water suggest a conversion factor between the Newton and the Celsius scale of between about 3.08 (12 °N = 37 °C) and 3.03 (33 °N = 100 °C) but since the objectively verifiable reference points given result in irreconcilable data (especially for high temperatures), no unambiguous "conversion" between the scales is possible.
|1 °N||= 3.030303030303 celsius (°C)||⇛|
|1 °N||= 145.45454545455 delisle (°De)||⇛|
|1 °N||= 37.454545454545 fahrenheit (°F)||⇛|
|1 °N||= 276.1803030303 kelvin (K)||⇛|
|1 °N||= 0.99999999999999 newton scale (°N)||⇛|
|1 °N||= 497.12454545455 rankine (°R)||⇛|
|1 °N||= 2.4242424242424 reaumur (°Re)||⇛|
|1 °N||= 9.0909090909091 romer (°Rø)||⇛|