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,
Les Spectacles de Paris the Concert Spirituel. For each theatre, it gives the new plays put on there that year, actors' first performances, anecdotes about the theatre world, actors, plays and comic-actors, and authors' and actors' obituaries. From 1792, the almanack also kept an important slot for provincial theatres (e.g. in Bordeaux, Lyon, Marseille, Nantes, Rouen, Toulouse and Lille) and the make-up of their troupes. The almanac was succeeded by the "Indicateur dramatique ou Almanach des théâtres de Paris" in 1798 and the "Almanach des spectacles de Paris" in 1799 and 1800, which gave way in the 19th century to the "Annuaire dramatique" (1805–1817),