The chess aficionados who frequent the Fifth and Market Street tables presumably don't know about the Chess Club at the Mechanics' Institute Library. Why else would they suffer the clamor, panhandlers, hecklers, and tourists to play a match in the chilly outdoors when this quiet, warm oasis is just blocks away? The oldest chess club in America, the Mechanics' was organized in 1854 to accommodate the Gold Rush frontier community. The library and club are housed in a historic building; its comfy leather chairs, oak-paneled walls, and musty scent are the perfect surroundings in which to test your strategy. In addition to match play, the association offers the critically acclaimed "Alex Yermolinsky Lecture Series," the ever popular "ChessChat With John Donaldson," children's classes for grandmasters-in-training, and the "Tuesday Night Marathon," a 25-year tradition for beginners and pros alike.