Abstract: A vibrating gyro operating on the principle of vibration waves traveling along a curved elastic surface transverse to the surface and being subjected to coriolis forces on rotation of the surface such as to shift the phase of the signal. The surface is provided by a spiral strip of metal having a vibration generator and detector at each end. Vibration waves are transmitted in both directions simultaneously and the phase difference between the received signals is determined. This gives a measure of the rotation rate. The gyro has great sensitivity and is particularly suited to gimballed systems. It therefore complements the vibrating gyro of U.K. Patent No. 2164749.