Since 2009, Paul Grundbacher of Switzerland has spent his winter free time building seven amazing marble machines. Crafted almost entirely from wood, each machine moves marbles about in a different and inventive way—“Qatro” shoots and catches marbles, “Stockwerke” advances them up a series of moving floors, “Chaos” does a bit a everything. Most of his machines are based on devices and plans he found on the Internet, but his most recent machine, “Archimedis,” is entirely original and by far the most elaborate.