Signedon instrument: N Bion A Paris
FunctionThe graphometer is a surveying instrument used for measuring angles in the horizontal as well as the vertical positions. It was invented by Philippe Danfrie at the end of the sixteenth century. Similar in use to surveying quadrants.
Historical AttributesThis instrument was owned and used by Edward Holyoke, president of Harvard College (1736-1769), in his surveys of Harvard buildings with John Winthrop, the Hollis Professor of Mathematics and Natural Philosophy.
ProvenanceEdward Holyoke, purchased circa 1710-1730; Edward Augustus Holyoke, his son; ... Andrew Nichols, a descendent of Holyoke, pre-1975; David P. Wheatland, 1975.