Scope and Contents: One six by eight inch diary, approximately 60 pp., titled "Veltkrug [World War] 1914-1918," illustrated with postcards and photographs pasted to many of the pages.  Written in narrative rather than journal form, in past tense, possibly toward the end of his service, and dedicated to his son Hans.  Describes his service on the front in France beginning in August, 1914, until he was wounded in September, 1915, and taken prisoner of war by the French.  In March, 1916, Kalkhofen was chosen by a team of Swiss doctors to participate in an experimental program to intern wounded soldiers from opposing sides in neutral Switzerland, where they could receive better care.  In May, 1916, he was taken by train to Switzerland, where he remained until July, 1918, when he was allowed to return to Germany.