Ernst Chladni at the understanding of electron orbitals. Since at least 1738, a musical instrument called a "Glasspiel" or "verrillon", created by filling beer glasses with varying amounts of water, was popular in Europe. The beer glasses were struck by wooden mallets shaped like spoons to produce "church and other solemn music". Benjamin Franklin was sufficiently impressed by a verrillon performance on a visit to London in 1757 that he created his own instrument, the glass armonica, in 1762. Franklin's armonica inspired several other instruments, including two created by Chladni. In 1791, Chladni invented the musical instrument called the "euphon" (not to
18th century 18th century The 18th century lasted from January 1, 1701 to December 31, 1800 in the Gregorian calendar. During the 18th century, elements of Enlightenment thinking culminated in the American, French, and Haitian revolutions. This was an age of violent slave trading, and global human trafficking. The reactions against monarchical and aristocratic power helped fuel the revolutionary responses against it throughout the century. In continental Europe, philosophers dreamed of a brighter age. For some, this dream turned into a reality with the French Revolution of 1789, though later compromised by the excesses of the Reign of Terror (1793–1794) under Maximilien