B66-76 COMBINATION BEVEL. Fritschler Patent. The "carpenter's rule" patented in 1858 by William Fritschler of Brooklyn is one of the rarest of the patented bevels, with only a handful of known examples. This one closely resembles the patent drawings, 12" boxwood arms with level vials in both arms, and a locking arm to allow it to be fixed at different angles. Clean with a few scratches and dings, both level vials original and wet, and clearly marked with the name and patent date. Good+ 1000-2000