What was discovered off coast of antiky thera?

Is this post-Roman era shipwreck? If so, various artifacts such as coins and statues were found. There were also copper helmets, bronze nails, and even the worlds oldest analog computer, the Antikythera mechanism. 

The answer is "he was bad enough in all conscience, but the devil himself could not temp him to turn slave-trader. satirical is a synonym for sarcastic. so when the author says that tom walker could not be tempted by the devil he does not literally mean "the devil" but he means that he is too morally upright to become a slave-trader.