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
Mercury-in-glass thermometer Medical Center and Las Piñas Hospital also made steps to ban the toxic chemical. The country was the first one to make a step to ban mercury from its health care system in Southeast Asia. Since European Union directive 2007/51/EC came into force on 3 April 2009, the UK Health Protection Agency (HPA) reported that mercury thermometers could no longer be sold to the general public. Shops holding stocks of unsold thermometers had to withdraw them from sale; mercury thermometers purchased before this date could be used without legal implications. The purpose of these restrictions is to protect the environment