Abstract: Apparatus for transmitting measurement information from a deep well being drilled to the surface comprises a receiving unit aboveground and a transmitting unit on a connecting section of the drill rod just above the drill bit. The transmitting unit comprises two spaced electrodes encircling the connecting section of the drill rod, means for connecting the electrodes to the terminals of a capacitor, an electrical source for charging the capacitor and a short circuiting switch for intermittently short circuiting the capacitor under control of one or another transducing elements for sensing the values to be measured e.g. the inclination of the bore, the direction of the inclination, the orientation of a directional drilling tool and temperature in the bore. The resulting coded energy pulses are transmitted through the earth to the receiving unit comprising an amplifying receiver connected to two spaced electrodes driven into the earth.