As well as the sitters, who share a marble-inlaid hardwood luohan chuang, in the background hangs a painting showing the bustling waterfront of Canton.
In its original Qing reeded and lacquered frame with two cloud-form iron bale handles, it measures 2ft 1in x 3ft 3in (63 x 99cm).
It is possible to date the painting by the various landmarks that post-date the Hongs fire of 1856. The vessel depicted in the harbour is thought to be the USS Takiang, a steamer built in 1862 in New York City. It was active in the China trade until 1864, when it was chartered by the British to Japan.
The alluring subject matter – one that hints at courtesan culture in Qing society – was copied many times later in the century.
However, this version, c.1870, once owned by Samuel Lowe Jr Antiques in Boston, bears comparison with a picture in the Peabody Essex Museum, Salem, and another oil on canvas offered by Sotheby’s New York in September 2014 as the property of Philadelphia’s Independent Seaport Museum.
The latter was unsold at $250,000-300,000 and Northeast’s expectations of $50,000-70,000 three years later proved closer to the mark. It was bought at the auction on August 18-20 at $85,000/£64,900 (plus 20% premium).