Experiment proving the strength of a Tunnel Book.
Place two cups with space between them. Put a piece of straight paper on top between the two cups. Place and count how many coins can be placed on the paper before the paper falls down.
Now place an accordion pleated piece of paper on top and between the cups. Place and count the coins placed on the accordion pleats.
Result: There are many more coins in place on the accoridon pleated paper. This proves how strong a Tunnel Book is.