Prehistoric people drank from just about anything that was hollow and would hold water. This included gourds, animal horns, coconut shells, egg shells, and even human skulls. The manufacture of glass vessels was common in Rome and in parts of the Roman Empire, but it seems to have all but died out within a century. Glass became a luxury item, and Venice had a near monopoly on the glass trade for centuries. By the 16th century, artisans in France, the Lowlands, and England began to produce glass. Glasses became common in England in the 1600s, but not much of it was exported to the Americas because they broke so easily. Puzzle Jugs, of the same period, were a challenge to drinkers. They displayed several spouts but only one worked. Double-handled jugs were made so that they could be easily passed from person to person. In colonial America, guests at an inn often drank from a communal bowl that was passed around the table, even when the guests were strangers to one another. In the late 1600s, Americans used leather drinking cups, which were stitched and waxed, and often fitted with a silver rim. Wooden and pewter tankards and earthenware vessels were common until the early 1800s when glassmaking became mechanized and more affordable. Nevertheless, the communal drinking cup, by then usually made of tin, was common in public places like schools, offices, and railroad cars until the early 1900s. The tin cup fell out of favor when doctors began lobbying for better health through sanitation, a crusade that led eventually to disposable paper and plastic cups and glasses. Non-disposable cups and glasses have to made stronger than ever before, not because they are dropped more often, but because they have to withstand the rigors of dishwashers.