B65-654 ADJUSTABLE DADO PLANE. Duval Patent. Patented in 1869 in Theodore Duval of Hartford, CT, and manufactured by the Hartford Plane Co. Consists of two bodies with overlapping cutters, designed to cut dadoes of different widths. The distance between the bodies is adjusted by a complex mechanism consisting of two brass plates with three thumbscrews each. Unlike most, this example is marked with both the manufacturer and the patent date, as well as a number of owners. The full story of the plane is in PTAMPIA I, pages 124-126, which describes it as a "true transitional" and "a bridge in the development of an efficient multi-purpose dado." This example is missing one screw attaching the brass adjustment plates and has some staining, but is an otherwise clean and complete example of a very rare plane. From the collection of Steve Dice. Good+ 600-1200