'when the wind changes' how did this phrase first come about?

Answer 1

It's a sailing term; i.e. The restrictions of sailing are such that you cannot sail directly into the wind so if you want to go "where the wind is comming from" you would have to sail back and forth at about 40degrees to where you want to go to. When the wind changes, it may allow you to sail directly there in a straight line - a big difference especially if you are Nelson or Captain Cook. I would think that the exact source of the expression is lost in the mists of time as it would have been something that people noticed as soon as sails where first used as propulsion thousands of years ago