law of diminishing returns. A concept in economics that if one factor of production (number of workers, for example) is increased while other factors (machines and workspace, for example) are held constant, the output per unit of the variable factor will eventually diminish.
History of glass. The history of glassmaking can be traced back to 3500 BCE in Mesopotamia, but Mesopotamians may have created second-rate copies of glass objects from Egypt, where this complex craft actually originated. Other archaeological evidence suggests that the first true glass was made in coastal north Syria, Mesopotamia or Egypt.
The first glass baby bottle in the U.S. was patented by Charles Windship of Roxbury, Massachusetts in 1841. His design featured a teardrop-shaped bottle with a glass tube coming down from the neck to act as a straw. Attached to the neck was a rubber hose, leading up to a bone mouth guard and a rubber nipple.