cover 1876 (18 Mar.) unstamped envelope (complete with letter from Hamilton) to New York State, marked "per S S Canima" in error which had sailed on 16 March, the cover held and carried on the George Cromwell on 31 March, showing "NEW-YORK/DUE5CTS." c.d.s.; envelope with small faults though an unusual mailing carried on the sole round trip of this substitute steamer