It has long been rumored that Harbin deliberately wrote some incorrect measurements in the famed "Harbin Book", forcing the reader to do a little more work when building from plans contained therein.

It's not too uncommon for small electronics manufacturers to epoxy over, change, or add false components to their boards in an effort to prevent piracy.

But what I really wanted to add is to Bill's mention of Dunninger's Encyclopedia. It's great to have around the house. If you have a layman guest, and they ask to peek at one of your magic books, hand 'em that one but only if they promise not to tell anyone else about it.

That reminds me of the lead-in to the French song on Martin Mull's first album. He brings out a bandana to tie around his neck, and says, "They say that there is a mistake in every bandana, because only God is perfect... Oh, look! I think I found it!"