cool things with wheels, since 2006
My father was born in 1929. He said that when he was a young boy, if someone left the door on a house open, even for just a few minutes, the entire ceiling would become black with flies due to all of the horse manure in the streets. His mother would try to suck most of them up with the vacuum cleaner. I always thought that movies set in this and earlier time periods would be more realistic if they included this scourge of horse manure and flies.