Notes: "This is an Ott Type 16 polar planimeter that was made for and sold by Dietzgen. There is no date, but the grey hammerite paint fairly screams 1950’s. It comes with everything: spare points for the weight, a screwdriver so you can install them, a checking rule, a clear plastic dust cover for the recording mechanism that can be left in place while you use the planimeter, and an excellent 12-page instruction book. "
