The Up and Down Book is a 1979 Sesame Street storybook featuring Ernie and Bert. The two friends have fun outside together, and find that they enjoy the same things in different ways. Ernie likes a big fountain to sail his boat, while Bert likes a small fountain to drink from. Ernie likes to walk through puddles, and Bert likes to walk around them. Ernie likes to play outside in the snow; Bert likes to stay inside and look at it.