9 Scientific, nautical, surveying, photographic, cinematographic, optical, weighing, measuring, signaling, checking, supervision, life-saving and teaching apparatus and instruments, namely, mechanical signs, mechanical signals, luminous signals, light emitting electronic pointers, railway traffic safety appliances; apparatus and instruments for conducting, switching, transforming, accumulating, regulating or controlling electricity; apparatus for recording, transmission or reproduction of sound or images; blank magnetic data carriers, calculating machines, data processing equipment and computers