Collection of Four Industrial Wooden Cased Testing and Measurement Instruments

Collection of four wooden-cased industrial measurement and testing instruments, including an American Thompson Improved Indicator set, a Dobbie-McInnes Large Size Steam Engine Indicator set, a Crosby Steam Gage and Valve Co. indicator set, and a Weston Potential Transformer Model 311 in a wooden housing. Each unit includes its original fitted wooden storage box with internal instructional paperwork, calibration cards, components, springs, and brass hardware.