b61-575 FARMER'S SIGHTING LEVEL. The Contour-O-Scope. A modern(ish) version of the water level, first invented by the Romans and developed during the Renaissance before spirit vials were common. It consists of two upright glass cylinders connected by a glass tube that allows water to flow between them; a line sighted across the water levels in both cylinders will be level. This version uses a solid aluminum body with the tube contained in it and a based to attach it to a tripod. Patented in 1938 by one Price Grieve of Sigourney, IA, and manufactured by the Farmers' Contour Co. of Denison, IA. 18" long, clean and complete with its original label and in what looks like a user made plywood box. Only one we've ever seen. From the collection of Don Rosebrook. Fine 300-600