This cup is made by Mayer, but I cannot identify the pattern. The pattern consists of a narrow band just below the rim, a broad band of rolling waves around the middle of the cup, and oval on one side of a steamboat with sails, an American flag at the stern, and "1849" at the bottom of the oval.  The cup shows signs of wear on the bottom, but otherwise is in excellent condition with a shiny glaze and no chips, crazes, or cracks.