John Thoreau's brother-in-law, Charles Dunbar, discovered a deposit of graphite in Bristol, New Hampshire, in 1821.
Besides the stone chamber, other points on the trail will include the Pencil Mill and the "Wheeler Farm" site.
World Heritage Site | Site of Special Scientific Interest | Peter Brook | Charlie and the Chocolate Factory | factory | Fear Factory | Factory | Fort McKavett State Historic Site | Fort Davis National Historic Site | Willy Wonka & the Chocolate Factory | Stony Brook University | The Factory | Michael Brook | Charlie and the Chocolate Factory (film) | C+C Music Factory | Stony Brook | Shout! Factory | Royal Ordnance Factory | Corner Brook | World Trade Center site | Knitting Factory | Hanford Site | Factory Theatre | Factory Records | Caughnawaga Indian Village Site | Brook Benton | Topper (archaeological site) | Stony Brook, New York | Savannah River Site | Royal Small Arms Factory |