Samuel Kern, who obtained patent #4,675 for this instrument on July 31, 1846, meant it to be "at once cheap and efficient, enabling one to use it as a compass for running lines, or for leveling, as may be required." A trough
compass, level vial, and outkeeper are inset into the face; the edge of the face is graduated to 30 minutes, and numbered in quadrants from north and south. Jacob Sensensy Danner (1807-1877) lived in Middletown, Va., and made instruments
for surveyors. Kern lived near Strasburg, Va.,
Ref: Charles Smart, The Makers of Surveying Instruments in America Since 1700 (Troy, N.Y., 1962), p. 35.
