I te tau 1758, i tētahi rā mahana i Cambridge, Ingarangi, i whakamātauria e Franklin rāua ko tana hoa pūtaiao a John Hadley mā te whakainu tonu i te pōro o tētahi thermometer mercury ki te ether, ā, mā te whakamahi i ngā pūkaha hei whakawaiwai i te ether. I ia whakawai i muri mai, ka pānuitia e te thermometer he pāmahana iti ake, i te mutunga ka eke ki te 7 °F (-14 °C). I whakaaturia e tētahi atu thermometer ko te pāmahana o te rūma i te 65 °F (18 °C). I roto i tana reta mā Evaporation Cooling, i kī a Franklin, "Ka kite te tangata i te tūponotanga o te whakamakuku i te tangata ki te mate i te rā mahana o te raumati". Pātai: He aha te pāmahana Celsius i te wā o te whakamātautau?
18 °C