What is Weather vane?
[[File:Windrichtungsgeber.jpg|thumb|right|250px|{{Center|A weather vane}}]] A '''weather vane''' is a device with a freely [[wikt:rotate|rotating pointer]] used to indicate the direction of the wind.<ref>{{cite web |url=http://www.dictionary.com/browse/weather--vane |title=weather vane |publisher=Dictionary.com, LLC |access-date=November 20, 2016}}</ref> Weather vanes served as simple devices for showing the direction of the wind and its speed for [[centuries]].<ref name=BeachSYN>{{cite web |url=http://classroom.synonym.com/history-wind-vanes-4298.html |title=The History of Wind Vanes |author=Emily Beach |website=Synonym |publisher=Leaf Group Ltd |access-date=November 20, 2016}}</ref> They were a critical tool for [[agriculture]], [[travel]] and [[shipping]]. They serve a largely decorative function today.<ref name=BeachSYN/> They have been replaced by specialized [[List of weather instruments|weather instruments]]. To work correctly a weather vane should be at the highest point of a building.<ref name=BeachSYN/> It needs to be as far away as possible from other things that might interrupt the wind.<ref name=BeachSYN/> The simplest form is a [[horizontal]] arrow or other form freely rotating on a vertical rod. When the wind blows, the arrow shows the direction and speed.<ref name=BeachSYN/> The earliest known weather was made by the [[astronomer]] Andronicus in 48 [[BC]].<ref name=Denninger>{{cite web |url=http://www.denninger.com/history.htm |title=A Brief History of Weather Vanes |author=Alfred H. and Beth R. Denninger |publisher=Denninger Weather Vanes & Finials |access-date=November 20, 2016}}</ref> It sat on top of the [[Tower of the Winds]] in [[Athens]].<ref name=Denninger/> It was between {{convert|4|ft}} and {{convert|8|ft}} long and was the shape of a [[head]] and [[torso]] of a man with the [[tail]] of a [[fish]].<ref name=Denninger/> The word 'vane' comes from the [[Old English]] ''fana banner''. This is related to the [[Old High German]] ''fano'' (cloth); from the [[Latin]] ''pannus'' (cloth or ra