What type of thermometer did the scientists make on the island?
The scientists actually made two thermometers. Firstly, a glass thermometer was constructed using methanol as the liquid. A very thin tube was made by heating glass in a furnace and then carefully stretching the molten glass. In order to calibrate the thermometer, we needed several known temperatures such as ice (0oC/32oF) or boiling water (100oC/212oF). We couldn’t use either: there was a distinct lack of ice on our Caribbean island and methanol boils at 67oC (153oF) so would have completely evaporated by the time the water reached 100oC. Instead we used sea water (which we guessed to be around 24oC/75oF) and room temperature (which we thought to be around 30oC/86oF in the lime factory).
