A US Offices in China 1886 cover has supplied one of the highlights of a major stamp auction in Switzerland, which took place from February 28 to March 3.
The cover, sent from the USS Palos / Asiatic Station to Washington DC, sold for $28,535, 7.9% above its $26,434 high estimate.
The reverse of the envelope displays a pair of 3c lilac Small Dragon issue stamps, tied by the Tientsin seal, while the front features a 5c brown Garfield with oval killer bar.
Its strong price is a product of the item's considerable rarity. It is the third earliest known Small Dragon / US combination cover and one of just 13 Small Dragon covers from 1886 recorded by Dr Kong Shiu-Ping.
Harmers Auctions described the lot as "an extremely early and highly important Small Dragon / US combination cover of exhibition quality".
The USS Palos saw active service 1870 and 1893, the majority of which was spent in Japanese and Chinese waters.
The sale also featured a strong performance for a rare 1903 French Offices in Yunnan Fu 75c deep violet on orange, bearing an inverted "Indo-Chine". The example is one of just three known.
Unused, and with the added attraction of its full original gum, the lot sold within estimate for $14,801.
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Leading the auction was a collection of prisoner of war correspondence from the Boer war, which included a variety of philatelic rarities from across the world.
It sold for $38,039 against a $7,924 high estimate.