Instruments, apparatus and contrivances for the transmissions or reception of sound, writings, images and signals, including radio signalling equipment, television equipment, radio transmitters, receivers, electron discharge devices, transistors and other semi-conductor devices, amplifying and public address equipment, loud speakers, telephones and telephonic apparatus, sound records and sound recording and reproducing apparatus, street traffic signalling apparatus, transformers, apparatus used for the projection of films bearing finished pictures, remote control apparatus and component parts of the foregoing,