This is a wooden compass with a paper card. The signature refers to Thomas Salter Bowles, who was baptized in Portsmouth, N.H., in 1785. An advertisement in the Portsmouth Oracle for May 31, 1806, notes that Bowles was a mathematical instrument
maker who had just taken a shop in Daniel Street, and that his wares included "Azimuth and brass Compasses, wood and Hanging Compasses." Bowles was still in business in 1821. Several Bowles compasses with different cards are known. Unlike most wooden compasses, this
one has a brass band around the outside of the box, and a brass needle ring graduated to 1 degree
Ref: Silvio A. Bedini, Early American Scientific Instruments and Their Makers (Washington,
D.C., 1964), pp. 124-126.