From the original book

(A quick hit of Joachim Ringelnatz; you can read a bit more about him and my foolish attempts at translation here)

Making Bubbles under Water
(Unter Wasser Bläschen machen)

Kids, a puzzle! Listen up!
Solve it and you’ll get some money. How can
One make bubbles under water?
You have to try this–absolutely–
In the tub. And when you solve this puzzle
You will laugh.