Augustus Prouty received patent # 224,040 on February 8, 1880 for the latch and #235,963 on December 28, 1880 for the lock used with his knobs. The knob pictured is an outside knob. The interior knob had a different design,M-12400. SeeAntique Builders' Hardwarepage 179. Click on each photo below to view additional images and information.