The ends of an oak tag strip are taped together to form a hoop, and the hoop is placed on top of a flask as in the photograph above. A screw on top of the hoop (lined up to be directly above the opening of the flask) falls into the flask when you quickly grab the ring from the side. (Striking the inside of the hoop with a quick sideways blow also works.)

This works in similar fashion to the way the tablecloth demonstration (12.12) and the pull-bottom-from-stacked-blocks demonstration (12.24) work. If you pull the oaktag hoop slowly, friction between the screw and the hoop pulls the screw sideways with the hoop. If, however, you do it quickly, you overcome friction, which cannot accelerate the screw significantly in the time it takes you to pull the hoop clear, and the screw falls straight down into the neck of the flask.