DescriptionMetagrad Philadelphia leveling rods, 6210 R-12, manufactured by Keuffel & Esser Co., circa 1940-1950. Wood and metal, 6 feet 10-1/2" inches high closed (slides open to 12 feet high) x 1-5/8" square body; two sections with a sliding clamp fixture. Item typically used by a surveyor or their assistant in surveying land. No target as issued. Metagrad was a trademark name for this product which the company promoted two important features: 1, it had "standard (Philadelphia) graduations" metal scales with painted measurements in black and red for accuracy and the capability to be replaced when damaged; 2, the method of mounting steel strips in the wood rod to maintain its accuracy and that the metal scales were independent of the wood so accuracy was improved. Metal plate at top with product name, maker and patent number (1934 patent) Keuffel & Esser Co. was located in Hoboken during this period and the item is considered as having been manufactured here.