Sholes and Glidden typewriter length. The redesigned platen also introduced the modern spacing functionality (horizontal and axial movement providing letter and line spacing, respectively). The cylindrical platen became "an indispensable part of every standard [typewriter]". By the end of 1872, the appearance and function of the typewriter had assumed the form that would become standard in the industry and remain largely unchanged for the next century. Although the machine possessed a cylindrical platen and what was essentially a QWERTY keyboard, two design elements that would later become essential were lacking: the ability to write in upper and lowercase letters and "visible" print. Although the
Typewriter Typewriter A typewriter is a mechanical or electromechanical machine for writing characters similar to those produced by printer's movable type. Typically, a typewriter has an array of keys, and pressing one causes a different single character to be produced on the paper, by causing a ribbon with dried ink to be struck against the paper by a type element similar to the sorts used in movable type letterpress printing. Commonly a separate type element (called a typebar) corresponds to each key, but the mechanism may also use a single type element (such as a typeball) with a different portion of