Question

What can go up a chimney down
but can't go down a chimney up?

Answer 1

 the idea of the umbrella going down the chimney down or up the chimney down but not being able to go down the chimney up or up the chimney up. The origins of this riddle are questionable, but it may be a reference to the storybook nanny character Mary Poppins, who went up the chimney with her umbrella.

Answer 2

i think the answer the answer is smoke or balloon