Fr Robert Warren
One of the church wardens at the Cathedral in Montreal owned a bookstore in the McGill University ghetto. He would put rather a lot of work into his window displays. One day there was a display of children’s religious books which contained one of those books with moveable cardboard bits in it. It was called Joseph in the Pit: A Popup Book. If you pulled a cardboard tab at the bottom Joseph would descend into the pit where he’d been cast by his brothers. If you pushed the tab he would pop up again.