This excerpt comes from the web:
https://www.monticello.org/site/research-and-collections/revolving-windsor-armchair
Revolving Windsor Armchair
Artist/Maker: Unknown[1]
Created: c. 1775
Origin/Purchase: Philadelphia
Materials: poplar, mahogany, maple, oak, and hickory
Dimensions: H before restoration 101.6; H of seat 36.8; D of seat: 58.4 (40 x 14 1/2 x 23 in.)
Provenance: Thomas Jefferson; by descent to Martha Jefferson Randolph; by gift to J.R. Kane; by gift to the American Philosophical Society in 1838
Historical Notes: When Jefferson returned to Monticello in 1776, he brought with him an uncommon revolving Windsor chair which he used “at Philadelphia while preparing the Declaration of Independence.”[2] At Monticello this consequential chair was used to form one of two reading-and-writing arrangements. The chair was apparently first used with a Windsor bench, and later with a sofa believed to have been made by Thomas Burling.
This comb-back chair, so called for the resemblance of the crest rail to a hair comb, is rare for its highly remarkable revolving mechanism, which probably was specified to the (unidentified) maker by Jefferson. The chair has two seats and “rotates on a central iron spindle and on rollers made of window sash pulleys set in a groove between the two seats.”[3] The chair has volute-carved ears at the ends of the crest rail and knuckle handholds on the arms. Unlike most comb-back Philadelphia Windsors, Jefferson’s chair has eleven spindles rather than the usual nine forming its back. The seat is round-rather than the customary D-shape with a pommel and “dished out” seat.
Later the chair was vastly altered in Monticello’s joinery. A new base with bamboo-turned legs, made either in the joinery or taken from another chair, replaced the original baluster-turned legs. The writing paddle was probably added when Jefferson switched the Windsor couch for the sofa.
Footnotes
↑ This article is based on Stein, Worlds, 264.
↑ J.R. Kane to the President of the American Philosophical Society, April 20 1838, American Philosophical Society. Kane, who received the chair from Martha Randolph, is clearly citing her account of the chair’s history.
↑ Charles Santor, Windsor Style in America (Philadelphia: Running Press, 1981), 199. See pages 199-200 for “The Re-creation of Thomas Jefferson’s Swivel Windsor.”