Although Hawkins failed in his attempt to construct a tunnel under the river thames, his successor Marc Isambard Brunel built one that opened to the public in 1843 (Henry Howe, Memoirs of the Most Eminent American Mechanics [1856], 428–41; ODNB description begins H. C. G. Matthew and Brian Harrison, eds., Oxford Dictionary of National Biography, 2004, 60 vols. description ends , 8:358). shuters hill: Shooters Hill, now located within the London borough of Greenwich. In 1800 Hawkins patented a claviol (claviole), a kind of compact, portable, upright pianoforte (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 ; List of Patents description begins A List of Patents granted by the United States from April 10, 1790, to December 31, 1836, 1872 description ends , 21). TJ bought one that same year from the inventor for $264, but he returned the instrument two years later because it would not stay in tune (PTJ description begins Julian P. Boyd, Charles T. Cullen, John Catanzariti, Barbara B. Oberg, and others, eds., The Papers of Thomas Jefferson, 1950– , 34 vols. description ends , 32:xxxv; 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 , 2:1014, 1016, 1018; TJ to Hawkins, 13 Apr. 1802 [DLC]).