What was Harry's most famous act?

Answer 1

If you separate magic tricks from escapology, then Houdini's most impressive trick was the disappearing elephant trick. Here an elephant was walked on to the stage and into a box; the box was rotated then opened. The elephant and keeper were gone. The trick is all the more impressive if you know that under the stage was a swimming pool so there were no trap doors. It's generally thought that Houdini did the trick with a slanted mirror inside the box. This method is still used today to make the Statue of Liberty (or the like) disappear.