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 London 18th-century London The 18th century was a period of rapid growth for London, reflecting an increasing national population, the early stirrings of the Industrial Revolution, and London's role at the centre of the evolving British Empire. In 1707, an Act of Union was passed merging the Parliament of Scotland and the Parliament of England, thus establishing The Kingdom of Great Britain. A year later, in 1708 Christopher Wren's masterpiece, St. Paul's Cathedral was completed on his birthday. The first service had been held on December 2, 1697, more than 10 years earlier. This Cathedral replaced the original St. Paul's which