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 then to the "Almanach des spectacles, par K.Y.Z." (1818–1824). Les Spectacles de Paris Les Spectacles de Paris was a French theatrical almanac which appeared in Paris (from the Duchesne press) from 1751 to 1797 without break. It followed the "Almanach des théâtres", printed by Ballard, in 1744 and 1745. Over its 46-year life, it changed its name several times : It was begun by abbot Joseph de La Porte, a playwright among other things. In it is to be found an annual run-down of the troupes of the Académie royale de musique, of the Comédie-Française, of the Comédie-Italienne, of the