Playing Marbles, little balls of marble, baked clay, agate, or other stony substance, used as toys for children. Marbles are made in immense quantities in Saxony for exportation to the United States, and to India and China. They are also largely manufactured in the agate mills at Oberstein on the Nahe, in Germany, particularly for the American market. The material used in Saxony is a hard calcareous stone, which is first broken up into square blocks with a hammer. These are then thrown 100 to 150 together into a mill, which is constructed of a stationary flat slab of stone, with a number of concentric furrows upon its face. Over this a block of oak of the same diameter, partially resting upon the small stones, is kept revolving, while water flows upon the stone slab. In 15 minutes the marbles are worn completely round, and are fit for sale. An establishment with three mills will manufacture 60,-000 marbles in a week. Agates are made into marbles at Oberstein by first chipping the pieces nearly round with a hammer, and then wearing them down upon the face of large grindstones.

The hard stones are managed with great dexterity by the workmen, who in a few minutes bring them into the shape of perfect spheres.