Notes: "This planimeter came from John Henschel & Co. of New York, who also supplied drafting tools and slide rules. Henschel appears to have been largely, if not exclusively, an importer, putting their name on slide rules by Nestler and planimeters by Reiss and Dennert & Pape, all from Germany. This planimeter, looking at the construction details, appears to have been made by Dennert & Pape."
