GYROSCOPIC COMPASSES, GYROSCOPIC MASTER COMPASSES, GYROSCOPIC REPEATER COMPASSES, GYROSCOPIC STEERING REPEATER COMPASSES, GYROSCOPIC BEARING REPEATER COMPASSES, GYROSCOPIC TARGET BEARING REPEATER COMPASSES, RECORDING RECEIVER COMPASSES, RECORDERS FOR INDICATING THE COURSE OF TRAVEL, TRACK TABLES USED WITH GYRO-COMPASSES, AZIMUTH CIRCLES USED WITH GYROSCOPIC REPEATER COMPASSES, SELF-STEERERS CONTROLLED BY GYRO-COMPASSES, [INCLINOMETERS USING ONE OR MORE GYRO-COMPASSES,] STABILIZERS USING ONE OR MORE GYRO-COMPASSES , TURN INDICATORS USING ONE OR MORE GYRO-COMPASSES