The Scarecrow watched the Woodman while he worked, and said to him:
"I cannot think why this wall is here, nor what it is made of."
"Rest your brains and do not worry about the wall," replied the Woodman; "when we have climbed over it we shall know what is on the other side."
...The Scarecrow climbed up the ladder first, but he was so awkward that Dorthy had to follow close behind and keep him from falling off. When he got his head over the top of the wall the Scarecrow said
"Oh, my!"

-L. Frank Baum, The Wonderful Wizard of Oz