Today’s invention is an aid to wash-day, when there is little wind.
A household might have a handful of special clothespegs.
Each of these would be used as usual to hold washing on the line but would also have a small motor and a floppy propeller (of the type employed in personal fans).
Some of these would be placed facing one way (orange) whilst the others would face in the opposite direction.
The pegs would make electrical contract with the metal washing line, so that current could be supplied from a battery in one of the posts.
A time switch would fire one set of propellers and then the other so that the line would swing with increasing amplitude and dry the clothes more effectively.