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,
Charlotte (1784 ship) Quebec merchant. A "Charlotte" was lost off Newfoundland in November 1818. However, there is no evidence to link the "Charlotte" that sank while sailing from Quebec to Liverpool with M'Call, master, to the "Charlotte" of this article. Another source notes that "Charlotte" continued to be listed in "Lloyd's Register" until 1821, but it is not unusual for "Lloyd's Register" to carry stale data for several years. An Urban Transit Authority First Fleet ferry was named after "Charlotte" in 1986. Citations References Charlotte (1784 ship) Charlotte was an English merchant ship built in the River Thames in 1784 and chartered in