Standard Units of Resistance, Inductance and Capacitance for Use in Electric Measuring Circuits; Electrical Bridge Circuits of the Decade, Slide-Wire, Dissipation-Factor, Vacuum-Tube-Characteristic, Capacitance, Resistance and Inductance Types and Accessory Electric Circuits and Components Required for Operation with the Bridge Circuits; Voltmeters, Ohmmeters, d'Arsonval Meters, Galvanometers, Wavemeters, Meters for Measuring Capacity, Impedance, Modulation, Sound-Level, Noise, Vibration, Distortion, Rate, Audibility, Frequency and Power, and Meters of the Hot-Wire, Heterodyne and Other Types and Accessory Electric Circuits and Components Required for Operation with the Meters; Electric Interpolation Apparatus; Indicators, Electronic Counters; Digital Voltmeters; Pulse Generators; Electrical Recorders; Industrial Electronic Stroboscopic and Other Instruments-Namely, Motion-Picture Recording Apparatus and Frames, Cameras, Tripods, Instrument-Carrying Cases, Lenses and Electric Flash Lamps; Wave-Form, Vibration, and Sound-Measuring Instruments and Analyzers; Calibration, Vacuum-Tube and Other Precision Forks; Voltage and Current Multipliers; Special Measuring Instruments for Making Measurements at Audio and Radio Frequencies; Measuring Net-Works; Standard-Signal Generators and Oscillators; Oscilloscopes, Gamma-Ray and Beta-Ray Counters; Frequency Standards and Monitors; and Range-Extension Units