Hong Kong Treaty Ports Shanghai 1871 (23 Oct.) envelope to Allahabad, India "via Galle & Calcutta" bearing 8c. orange tied by a fine strike of type 1 "S1" in blue, the reverse with Shanghai c.d.s. in blue, Hong Kong (29.10), Calcutta (25.11) and Allahabad arrival (27.11) datestamps. A good cover. Photo