In the late 1800s, barkeeps beat eggs, rum, and spices in special bowls inscribed with the name of the drink, ladling the foamy liquid into cups, nicknamed shaving mugs, to be topped with more liquor and hot milk or water. By the 1930s and ’40s, Fire-King and other manufacturers were mass-producing colorful milk-glass and ceramic versions. So many were made that the sets—like the ones shown here, from the collection of a New York City bar called Tom and Jerry’s—are easy to find on eBay and in antiques stores today.