Archive of Collections



Details and Image



TypeModel No.MakerCountryConstruction
Material
DateScale LengthArea of Use
Hybrid
Willis Improved Planimeter
James L. Robertson & Sons
USA
Chrome plated brass
ca. 1902
N/A
General area measurement

Notes: "The improved Willis Planimeter incorporates elements from the polar planimeter (a scale, on-board) and the hatchet planimeter (the knife-edged wheel recording mechanism). The rotating triangular ruler provided multiple scales for different drawing scales. This one displays patent dates from 1896 and 1901, and the serial number is 6061."


Image 1