Black cats pilot a squadron of flying jack-o'-lanterns in this fairly unscary Halloween postcard - a young fellow in Lewiston, Maine named Charles sent it to his Aunt Nettie ninety-nine years ago.  Beyond postcards, balloons have inspired artists of all sorts since they first took to the skies - have a look at some of the Air and Space Museum's other superb works of balloon art, and have a happy Halloween.