With this great improvement over the original method both the ball and tube can be examined before and after you perform it! All without any palming or switching of any kind!
You show a solid brass tube and solid steel ball to your spectators. They can plainly see that the steel ball is too big to fit into the brass tube.
You offer to show them a little trick and now they see the steel ball slowly sink down into the tube and then slowly rise back to the top of the tube!
Immediately you can hand out the ball and tube for examination. They try themselves, but the ball won't fit inside the tube no matter how hard they try!
Everything can be closely examined without the fear of detection or without having to resort to any switching or palming! You'll love the ingenious method!