Abstract: Apparatus and method for determining a deviation of a body from a horizontal plane is disclosed. Attached to the body is a curved surface with a liquid conducting material moving freely thereon. Associated with the surface are electrodes at preselected positions and a surface at ground potential. As the liquid conducting material moves on the inner portion of the curved surface, the liquid conducting material provides a conducting path between the electrodes providing a resulting electrical activity such as a current flow. The electrical coupling of the electrodes is identified and the electrode(s) so activated identify a position on the curved surface and consequently when the curvature of the surface is known, a deviation from the horizontal plane can be determined. The position of the electrodes and the electrical structure thereof provide suitable signals for use by digital signal apparatus.