In the episode "Pirates," a museum curator and her companion have pulled a 250-year-old treasure chest from the ocean floor. When they pry it open, the contents include jewelry, coins, a ship's log book and several rolled-up letters. All of the paper items are perfectly dry: the log book can be opened and read, and the letters can easily be unrolled. Even in a pitch-sealed chest, that's highly unlikely after 2 1/2 centuries underwater. The wood and pitch would both deteriorate (salt water is extremely corrosive), and the paper should be damp and crumbly, at the very least. Even more likely, it would have become a lump of unreadable sludge.
 
 

Look very closely at the Battle of Bull Run scenes about halfway through part 1 of this miniseries. See the 2-story farmhouse? The one with the little old lady inside? The one that gets hit and blown up by cannon fire? OK, run the tape or dvd back to the battle going on in the front yard just before the house is hit. Watch the upper left portion of the screen -- the sky above the house -- and you'll see a helicopter fly from left to right, vanishing at the top of the picture. You can't tell from the perspective whether it's a full-sized copter or a "drone" (remote controlled) miniature copter of the sort often used to take aerial footage, but either way, it's a hilarious goof!