no idea what they were called: two very heavy balls on a string. The object of the game was to grab the string in the middle and flip the balls til they kept clanging against each other. OH did that smart when you did it wrong an they hit body parts - mostly the knuckles.
Then I had a thing that looked like an hourglass. The object of the game was to make it roll back and forth on a string controlled by sticks at each end. Never got that to work either.
I was very glad when I discovered boys.