Medical thermometer Bahamas, Belize, and the Cayman Islands. Prominent Dutch mathematician, astronomer and physicist Christiaan Huygens created a clinical thermometer in 1665, to which he added an early form of the centigrade scale by setting the scale to the freezing and boiling points of water. By 1742 Swedish astronomer Anders Celsius created the Celsius temperature scale that was the reverse of the modern scale, in that "0" was the boiling point of water, while "100" was freezing. It would later be reversed by Swedish botanist Carolus Linnaeus (1707–1778) in 1744. Working independently of Celsius, the Lyonnais physicist Jean-Pierre Christin, permanent secretary of
Anders Celsius conducted with his assistant Olof Hiorter, and he was the first to suggest a connection between the aurora borealis and changes in the magnetic field of the Earth. He observed the variations of a compass needle and found that larger deflections correlated with stronger auroral activity. At Nuremberg in 1733, he published a collection of 316 observations of the aurora borealis made by himself and others over the period 1716–1732. Celsius traveled frequently in the early 1730s, including to Germany, Italy and France, when he visited most of the major European observatories. In Paris he advocated the measurement of an