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,
Land Ordinance of 1784 Land Ordinance of 1784 The Ordinance of 1784 (enacted April 23, 1784) called for the land in the recently created United States of America west of the Appalachian Mountains, north of the Ohio River and east of the Mississippi River to be divided into separate states. The ordinance was adopted by the United States Congress of the Confederation under the Articles of Confederation. Thomas Jefferson was the principal author. His original draft of the ordinance contained five important articles: In the late eighteenth century, slavery prevailed throughout much more than half the lands of Europe. Jefferson designed the ordinance to