3" dia. and 3/8" thick. c. 1910. Stamped lithograph metal with glass cover. Wonderful detailed graphics of 10 players, 2 umpires, 2 coaches. Text reads "National Baseball Puzzle/Patent Applied For" around pitcher. Along base lines reads "The Trick - Hold 'Matty' (refers to Christie Mathewson) in box while Evers (refers to Johnny Evers of Cubs Infielders - Tinker to Evers to Chance fame) makes home run without running off diamond. Other base line reads "Popular Games Co. New York." Text along outer rim reads "We Also Manufacture Inside Baseball Big League Games Played In Your Home/Close Scores, All Teams/Ask Dealer Or Us For Particulars." Game holds 2 metal balls that are intended to start with pitcher, follow recessed area to batter and around base line to score home run. Outside of case shows wear, most gold luster highlights are gone. Tin litho playing surface shows little wear. There are 2 tiny "flea bite" chips on the glass cover at the outside edge. Overall Fine. First we've seen. Rare and significant.