GYROSCOPIC COMPASSES, GYROSCOPIC COMPASS RECEIVING SETS FOR PICKING UP SIGNALS TRANSMITTED BY A GYROSCOPIC COMPASS, GYROSCOPIC COMPASSES WITH DISTANCE TRANSMISSION, OTHER APPARATUS WHICH ARE USED IN CONNECTION WITH GYROSCOPIC COMPASSES-NAMELY, AZIMUTH READERS, COURSE AND RUDDER POSITION RECORDERS, RECORDING APPARATUS, AND MEASURING AND OBSERVATION INSTRUMENTS WITH BUILT-IN GYROSCOPES