Interesting covers that need further research. Addressed to James Field, Purchase post office, New York. Two letters are from California with the notations "from the mines San Francisco" and "from California" The former has a large San Francisco postmark with the 40 cross country rate inside the dial. The second is a black San Francisco postmark with the box 40 mark. A third letter is probably the first of the series as it is from Baltimore and has the notation "from ship board to California Valparaiso" That cover bears blue Baltimore, SHIP and 7 markings. No contents. All three covers show wear but are a rare grouping.