This exceptionally large pair of cabinets is likely to have been laden with anything from food to books or paintings, and carried at either end of a long carrying pole. Consequently, the stress placed on the frame required a particularly strong construction reinforced with inlaid hardware.
A very similar pair of travelling bookcases, formerly from the collection of the Museum of Classical Chinese Furniture, was sold at Christie's New York, 19 September 1996, lot 17. For a discussion of metal fittings on bookcases, see an article by Curtis Evarts, "Uniting Elegance and Utility: Metal Mounts on Chinese Furniture", JCCFS, Summer 1994, pp. 27-47. A larger version of this bookcase, but without side posts and connecting top rail, from the Mr. and Mrs. Robert P. Piccus Collection, was sold at Christie's New York, 18 September 1997, lot 75.