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.
Of all my inventions, the glass armonica has given me the greatest personal satisfaction.. Benjamin Franklin was inspired to create his own version of the armonica after listening to a concert of Handel's Water Music which was played on tuned wine glasses. Benjamin Franklin's armonica, created in 1761, was smaller than the originals and did not require water tuning.