Encyclopedia Britannica "Science & Technology: Daniel Gabriel Fahrenheit" [1]
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Fahrenheit describes, in Latin, these numerical choices in the following paper: Fahrenheit, D. G. (1724). «Experimenta et Observationes de Congelatione aquae in vacuo factae». Philosophical Transactions of the Royal Society33 (381–391): 78. doi:10.1098/rstl.1724.0016.