Abstract: Cross slope sensing apparatus for directly and accurately measuring the cross slope of a surface finishing machine cutting blade regardless of the depth or angle of the cut, or the looseness of the attachment of the blade to the machine. The apparatus includes a sensor support table that rests on the upper edge of the cutting blade and linkage for maintaining the longitudinal axis of the table parallel to the longitudinal axis of the machine during selective positioning of the cutting blade. Since the table rides on the upper edge of the cutting blade while remaining forwardly oriented, the inclination of the table reflects the true cross slope of the blade and is directly measured and controlled by a sensor positioned on the table.