Seven-Day Terror

Things just vanished. It was simple. As a matter of fact, it was child's play!
Is there anything you want to make disappear? Clarence Willoughby asked his mother.
A sink full of dishes is all I can think of. How will you do it?
I just built a disappearer. All you do is cut the other end out of a beer can. Then you take two pieces of red cardboard with peepholes in the middle and fit them in the ends. You look through the peepholes and blink. Whatever you look at will disappear.
Oh.
But I don't know if I can make them come back. We'd better try it on something else. Dishes cost money.
As always, Myra Willoughby had to admire the wisdom of her nine-year-old son. She would not have had such foresight herself. He always did.
You can try it on Blanche Manners' cat outside there. Nobody will care if it disappears except Blanche Manners.
All right.
He put the disappearer to his eye and blinked. The cat disappeared from the sidewalk outside.
His mother was interested. I wonder how it works. Do you know how it works?
Yes. You take a beer can with both ends cut out and put in two pieces of cardboard. Then you blink.