Meteorology known as the first "anemometer". In 1607, Galileo Galilei constructed a thermoscope. In 1611, Johannes Kepler wrote the first scientific treatise on snow crystals: "Strena Seu de Nive Sexangula (A New Year's Gift of Hexagonal Snow)". In 1643, Evangelista Torricelli invented the mercury barometer. In 1662, Sir Christopher Wren invented the mechanical, self-emptying, tipping bucket rain gauge. In 1714, Gabriel Fahrenheit created a reliable scale for measuring temperature with a mercury-type thermometer. In 1742, Anders Celsius, a Swedish astronomer, proposed the "centigrade" temperature scale, the predecessor of the current Celsius scale. In 1783, the first hair hygrometer was demonstrated by
Candy thermometer Candy thermometer A candy thermometer, also known as a sugar thermometer, or jam thermometer is a cooking thermometer used to measure the temperature and therefore the "stage" of a cooking sugar solution. (See Candy making for a description of sugar stages.) These thermometers can also be used to measure hot oil for deep frying. There are several kinds of candy thermometers available. These include traditional liquid thermometers, coil spring "dial" thermometers and digital thermometers. The digital thermometers tend to read the temperature more quickly and accurately, and some models have an alarm when the thermometer hits a certain temperature. Many