German-born American inventor who developed the Linotype machine.

A precocious boy, Mergenthaler was anxious to study engineering, but his father, burdened with financing the higher education of older sons, found the expense beyond his means. He was apprenticed to a watchmaker at age 14 and attended technical school classes at night. In 1872 he emigrated to the United States, becoming a citizen in 1878. While employed in the Baltimore machine shop of a relative, he worked on plans for a device to make type molds of papier-mâché. This device proved impracticable, but Mergenthaler became dedicated to the problem involved—setting type by machine. In 1886 he produced his Linotype, which, by bringing copper matrices into brief contact with a molten but fast-cooling alloy, rapidly molded column widths of type. The machine reduced costs by speeding up the printing process; hence it fostered a dramatic expansion of all areas of publishing. Mergenthaler later patented other successful inventions, but developing the Linotype remained his life interest.