In the latter part of 1815 Jefferson made two lengthy visits to his Bedford County estate, Poplar Forest, a principal goal of which was observing and calculating the height and latitude of the nearby Peaks of Otter. This group of travel receipts documents a portion of the first of these trips. Jefferson had arrived at Poplar Forest on 21 Aug. 1815 for a prolonged stay. On about 10 Sept. he left on a brief journey to Buckingham Court House (later Buckingham) in order to testify on 12 Sept. regarding the disposition of his brother Randolph Jefferson’s estate. The first four receipts in this group resulted from this trip. On 13 Sept. Jefferson’s friends José Corrêa da Serra and Francis W. Gilmer joined him at Poplar Forest. The three men stayed from 17 to 19 Sept. 1815 at Mount Prospect, the Bedford County home of Jefferson’s friend Christopher Clark, which was their base as they conducted observations in the surrounding countryside. The final two receipts record some of Jefferson’s expenses during this scientific expedition. Local report described the trio as traveling “in a vehicle much resembling a mill hopper,” with the goal of “taking the elevation of the Peaks of Otter and exploring the Sides of them for Subjects botanical.” From Clark’s residence they proceeded to Natural Bridge, where they concluded their studies. Corrêa da Serra and Gilmer departed together from there for further extended travels. Jefferson made additional measurements and calculations of the Peaks of Otter in November 1815 on a succeeding visit to Poplar Forest (MB description begins James A. Bear Jr. and Lucia C. Stanton, eds., Jefferson’s Memorandum Books: Accounts, with Legal Records and Miscellany, 1767–1826, 1997, The Papers of Thomas Jefferson, Second Series description ends , 2:1313–4, 1316; Peachy R. Gilmer to Francis W. Gilmer, 3 Oct. 1815 [ViU: Gilmer Family Papers]; Jefferson’s Calculations of Altitude of the Peaks of Otter, editorial note and group of documents printed below at 10 Nov. 1815).