The Wizard of Oz by Lynam Frank Baum Chapter 12 Page 23

But the wicked creature was very cunning, and she finally thought of a trick that would give her what she wanted. She placed a bar of iron in the middle of the kitchen floor, and then by her magic arts made the iron invisible to human eyes. So that when Dorothy walked across the floor she stumbled over the bar, not being able to see it, and fell at full length. She was not much hurt, but in her fall one of the Silver Shoes came off; and before she could reach it, the Witch had snatched it away and put it on her own skinny foot.

The wicked woman was greatly pleased with the success of her trick, for as long as she had one of the shoes she owned half the power of their charm, and Dorothy could not use it against her, even had she known how to do so.

The little girl, seeing she had lost one