It is Opening Day at New York’s Polo Grounds, April 29, 1886. The image stops time at a precise moment in history, a moment captured on glass in the “detective camera” by a spectator. It is the bottom of the fourth inning of a game between Boston and New York: Hoss Radbourn is on the mound making his debut as a Red Stocking; Mickey Welch is at bat; John M. Ward is on deck. Play ball!