Mechanical integrator built by Keuffel & Esser Co. and used at the NASA Langley Research Center, housed in its original 30.5″ x 6.5″ x 3.5″ wooden case, bearing multiple NASA calibration and property tags (and a detached "NACA/Langley Field" label). The device could be used to find the integral of a curve, that is to say the area between the curve and a given straight line. Includes a calibration sheet dated 1981. In very good to fine condition.
