China - The Yang-Tse-Kiang. from the Sea to Nanking.

A rare proof lithograph probably done shortly after the surveys were made by the Captains, Bethune, Kellett & Collinson. This proof may have be done in Calcutta, India and was one of only a few which would have been printed by lithography. One of these would have been sent back to the Hydrographic Office of the Admiralty to be engraved and tidied up and possibly combined with other surveys. When the engraving, on steel or copper plate, was completed the publishers line with date would appear below the map and an Admiralty logo would also appear on the finished chart.

Because of the time taken to publish at the Admiralty a few of the proof charts may have been available to ships that needed them. This proof chart has been used and pencil tracks appear on the map.