An 18th Century automaton that could beat human chess opponents seemingly marked the arrival of artificial intelligence. But what turned out to be an elaborate hoax had its own sense of genius, says Adam Gopnik.Lately I've been thinking a lot about the Turk. That sounds, I know, like a very 19th Century remark. "Have you been thinking about the Turk?" one bearded British statesman might have asked another in the 1860s, with an eye to the Sublime Porte and Russian designs on it, and all the rest....