Letters between members of the Cowan family, largely to John from his mother Ann and brother Michael, 1866-1869; letters between Michael Cowan and his mother, siblings and children, whilst he was aboard HMS SPHINX, 1870-1873, with a photograph of the ship and crew from a family album marked Emma L. Cowan; letters largely to John Cowan from his brother Michael (some for which he gives HMS CLYDE as his address) and his mother, and some letters to Michael's daughter Emma Louisa Kay Cowan (later Lady Porter, also known by the nickname Lutie) from various correspondents, 1876-1878; letters between members of the Cowan family, largely Michael to his daughters, addressed from HMS TEMERAIRE, 1879-1880; letters to John from Michael and Ann, 1881-1884, whilst Michael was at Orton Barracks, including Ann's last letter and correspondence relating to her death and will.