The Jerry Slocum Collection of mechanical puzzles embodies a lifetime pursuit of the intriguing and the perplexing. The result is the largest assemblage of its kind in the world, with over 30,000 puzzles and 4,000 puzzle related books. Unlike word or jigsaw puzzles, mechanical puzzles are hand-held objects that must be manipulated to achieve a specific goal. Popular examples include the Rubik's cube and tangrams. The puzzles in the collection represent centuries of mathematical, social, and recreational history from across five continents.

About 400 puzzles from the larger collection are on display at the Lilly Library in the Slocum Puzzle Room.