Series consists of letters written to Cotsworth, personal notes (mostly written on envelopes and scraps of paper), drafts of printed material that may have been used in his publications, and miscellaneous articles written by other individuals. All of the records deal with calendar reform, but the personal notes reflect the wide range of Cotsworth's interest in this matter . They include notes taken on his travels to Stonehenge, Egypt, Northern British Columbia, and Alaska. The personal notes also include descriptions, even lists, of photographs taken on his trips. The articles written by other individuals deal with calendars and religious topics.