Abia B. Thorn (1795–ca. 1835), brick mason, was born in Burlington, New Jersey. He was among the Philadelphia workmen recruited in 1819 to build the University of Virginia, and TJ praised his brickwork on the Rotunda when he left Charlottesville five years later. By 1825 Thorn worked as a bricklayer in New York City, and two years later he became a member of the General Society of Mechanics and Tradesmen of the City of New-York. Thorn likely died in New York, where his wife remained after his death (PSC-Hi: Chesterfield Monthly Meeting Records; note to University of Virginia Workmen to TJ, 9 Feb. 1820; TJ’s Recommendation of Thorn, 25 Sept. 1824; Longworth’s New York Directory description begins Longworth’s American Almanac, New-York Register, and City Directory, New York, 1796–1842 (title varies; cited by year of publication) description ends [1825]: 415; [1835]: 645; [1836]: 654; Thomas Earle and Charles T. Congdon, eds., Annals of the General Society of Mechanics and Tradesmen of the City of New-York, from 1785 to 1880 [1882], 413).

Nathaniel Chamberlain (1784–1848), brick mason, was a native of Salem, Massachusetts. He worked in Philadelphia before going to Charlottesville, where he did brickwork for the University of Virginia Rotunda, 1823–25. In the latter year Chamberlain considered moving to New York, but he was still in Albemarle County at the beginning of 1827. He returned to Salem by 1834, and in 1846 he became the superintendent overseeing construction of the Beacon Hill Reservoir in Boston. Chamberlain died on a visit to Albemarle (Brockenbrough to TJ, [received 19 Dec. 1822], and 21 Jan. 1825; petition of Albemarle Co. citizens to the General Assembly of Virginia, 17 Jan. 1827 [Vi: RG 78, Legislative Petitions, Albemarle Co.]; Memorial of Citizens of Salem, Massachusetts, In relation to the Currency. April 14, 1834 [23d Cong., 1st sess., Executive Documents, no. 327], 9; History of the Introduction of Pure Water into the City of Boston [1868], 101; Boston Daily Atlas, 11 Mar. 1848; Albemarle Co. Will Book, 18:406; gravestone inscription in Lewis-Clarkson family graveyard, Albemarle Co.).

sharp sand is “hard, angular, gritty” (OED description begins James A. H. Murray, J. A. Simpson, E. S. C. Weiner, and others, eds., The Oxford English Dictionary, 2d ed., 1989, 20 vols. description ends ). A rubbed (rubed) brick is “a soft clay brick with a smooth polished surface, chiefly used for ornamental and high-quality brickwork” (OED description begins James A. H. Murray, J. A. Simpson, E. S. C. Weiner, and others, eds., The Oxford English Dictionary, 2d ed., 1989, 20 vols. description ends ). killed: “kilned.”

In an undated proposal made prior to this agreement, Thorn and Chamberlain offered to do the Rotunda’s stonework, laying the stone and grouting the walls at a rate of 75 cents per perch, with the stone, lime, and sand provided by the university. They would perform the brickwork, laying and grouting the walls for $2.75 per thousand bricks, with the bricks, lime, and sand also supplied to them. Thorn and Chamberlain would also furnish the laborers and attendants and raise the scaffolding. In a subjoined proposal, for an additional $50 per month Thorn offered to oversee the requisite brick making and provide the necessary instructions for preparing the yard (MS in ViU: PP; in an unidentified hand, signed by Thorn on behalf of himself and Chamberlain; endorsed by Brockenbrough: “Proposals of Thorn & Chamberlain”).