downwardly the rod 94 will move down and rotate about its longitudinal axis due to the engagement of the brake shoes with the carriage wheels and such movement will cause the rod 94 and the lever 98 to rotate against the tension applied by the tension spring 100 thus braking force will automatically be increased when the machine 10 is making a deep cut in the pavement and will automatically be decreased when relatively shallow cuts are being made the usual practice followed in opening and cleaning expansion joints and random cracks in pavement is to cut the pavement to a depth of about three quarters of an inch setting prior art machines to make a cut of the proper depth has always been a more or less hit or miss proposition in that depth gages which compensate for cutter wheel wear have heretofore been nonexistent to the best of our knowledge therefore the machine 10 is equipped with a wear compensating depth gage 110 which as shown in fig3 and 7 includes a pointer 112 extending from the rear cross member 26 of the carriage 12 toward a depth scale plate 114 carried on the arcuate plate 35 of the shroud 14 the depth scale plate 114 is divided into a lower group of three segments 116a 116b and 116c and an upper group of three segments 117a 117b and 117c for segment matching purposes as will hereinafter be described in detail segment 116a of the lower group is identified so as to match the lower segment 117a of the upper group segment 116b matches segment 117b and segment 116c matches segment 117c such matching identification can be accomplished in any convenient manner such as by employing suitable alphamerics.