Mechanical Gyroscope shows earth’s rotation of 15 degrees per hour

NOTE: These are *not* gyro compasses. Please disregard me referring to them as gyro compasses! Sorry about the audio desync on the section for Gyro #2. Video editor giving fits. Otherwise, yeah, 3 mechanical air powered gyroscopes all agree in a controlled test that the earth rotates at about 15 degrees per hour which is one turn in 24 hours.