Optician more important and dignified. Far-sighted or aging colonial Americans imported spectacles from Europe. Spectacles were primarily for the affluent and literate colonists, who required a valuable and precious appliance. Benjamin Franklin in the 1780s developed the bifocal. Bifocal lenses advanced little in the first half of the 19th century. The terms bifocal and trifocal were introduced in London by John Isaac Hawkins, whose trifocals were patented in 1827. In 1884 B. M. Hanna was granted patents on two forms of bifocals which become commercially standardized as the "cemented" and "perfection" bifocals. Both had the serious faults of ugly appearance, fragility,
HMS Crescent (1784) HMS Crescent (1784) HMS "Crescent" was a 36-gun "Flora"-Class frigate of the British Royal Navy. Launched in 1784, she spent the first years of her service on blockade duty in the English Channel where she single-handedly captured the French frigate, "La Reunion". In 1795, "Crescent" was part of a squadron commanded by George Elphinstone, that forced the surrender of a Batavian Navy squadron at the capitulation of Saldanha Bay. After serving in the West Indies, "Crescent" returned to home waters and was wrecked off the coast of Jutland on 6 December 1808. Britain's early preference for smaller warships was mainly