Electrical Apparatus, Machines, and Supplies, Parts Thereof and Accessories Therefor-Namely, Telephone Transmitting and Receiving Apparatus and Component Parts; Telephone Switchboards and Central Office Apparatus and Component Parts; Selective Switching and Selective Signaling Apparatus and Component Parts; Telegraph Transmitting and Receiving Apparatus and Component Parts; Telegraph Central Office Equipment; Electrical Wires, Cables, and Conductors; Cable Terminating Equipment; Electric Circuit Protective Apparatus; Telephone Repeaters, Telegraph Repeaters, Vacuum Tube Amplifiers, and Similar Signal-Current Regenerating and Amplifying Devices and Component Parts; Speech and Other Sound Amplifying Apparatus and Component Parts; Radio and Carrier Current Transmitting and Receiving Apparatus and Component Parts; Communication Circuit Components Such as Attenuation Equalizers, Electric Wave Filters, Electrical Networks, Frequency Stabilizers, Loading Coils and Auxiliary Equipment; Photoelectric Devices; Piezo-Electric Devices; Electron Discharge Devices; Electric Insulators, Insulating Compounds and Materials; Submarine Signaling Apparatus; Picture Transmitting and Receiving Apparatus; Electromagnetic Light Modulators; Electric Wave-Form Indicators and Recorders