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
What Was Missing this episode, Finn, Jake, Princess Bubblegum, and Marceline form a band in order to defeat the Door Lord and recover what the creature had stolen from them. Sugar noted that while the episode may appear to be about friendship, it is really about the power of telling the truth, as exemplified by the episode's songs. Episode composer Tim Kiefer played all of the conventional instruments himself, and used unique instruments, like a Game Boy, to make some of the loops heard in the episode. The episode was watched by 2.185 million people and caused a major controversy due to the