Swivel chair

A swivel, spinny, or revolving chair is a chair with a single central leg that allows the seat to rotate 360 degrees to the left or right. The first swivel chair was invented by Thomas Jefferson, and is purported to be the chair on which he drafted the United States Declaration of Independence in 1776. Swivel chairs may have wheels on the base allowing the user to move the chair around their work area without getting up. This type is common in modern offices and are often also referred to as office chairs. Office swivel chairs, like computer chairs, usually incorporate a gas lift to adjust the height of the seat, but not usually large (e.g. recliner) swiveling armchairs. A draughtsman's chair is a swivel chair without wheels that is usually taller than an 'office chair' for use in front of a drawing board. They also have a foot-ring to support the legs when it is not possible to reach the ground.