Patent No. 201,064. Filed by George N. Stearns through the US Patent Office. Knurling and square bit are in immaculate condition. I believe this to be the original paint. Stamped 'MAR. 5. 78.' on the underside. This expands by loosening the lower lock nut and turning the top collar. Brilliant design, extra fine condition.
Information on this patent can be found here via datamp.org
**All edge tools may need to be sharpened and/or honed before use**