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,
Thomas Evans (bookseller, 1742–1784) Evans died on 30 April 1784. Evans wrote or edited: Evans left a widow Ann and a young son, Robert Harding Evans. Thomas Evans (bookseller, 1742–1784) Thomas Evans (1742–1784) was a London bookseller, one of two of the same name in the middle of the 18th century. Evans served an apprenticeship with Charles Marsh of Round Court and Charing Cross, and opened a bookshop in the Strand, London. He published works on English literature and antiquities, many edited by himself. A leading member of the booksellers' club in the Grecian Coffee-house, to which Thomas Davies belonged, Evans was popular. Unlike