Do you think that I am worthless? Observe that I am furnished with a glass at both ends of my pipe. Consider that by looking through one of them, you will see whatever you wish to behold. What, in the whole universe, would you wish to see?

Your father the Sultan, you say? There you see him with his courtiers.

The Princess Nouronnihar? Of course you do. Well there she is, at her toilet laughing, with her women about her.

Ha! Now, tell me what I am worth!

The Magic Perspective Glass in Prince Ahmed and the Fairy Paribanou, Blue Fairy Book. Vintage postcard, artist unknown.