cover 1873 (10 May) envelope addressed to Boston "pr Pacific Mail" bearing 10c. (straight edge at right) tied by hollow star cancel with a fair strike of "U.S. POSTAL AG'CY/SHANGHAI" type IIb c.d.s. alongside, the reverse with double oval "Forwarded by/RUSSELL & CO. SHANGHAI" dated forwarding agent's cachet; fine and attractive. Photo