Notes: "This appears to be an excellent copy of the Amsler Type 4 planimeter. The only brand marking is on a metal plate on the box and says, “Yasukawa & Co. Yokohama”. Yasukawa may have been the manufacturer, but it is much more likely that they were the retailer and the planimeter was made by someone else in Japan, perhaps Tamaya. There is no brand name, model name, or serial number on the planimeter itself."
