Notebooks is the largest in the collection. Most date from Watt's work in the Breckland area from 1931 to the 1970s but there are also notebooks recording earlier research on the regeneration of British woodlands and a few from visits overseas, including a visit to Germany in 1931, also documented by a series of photographs (Section E), and a visit to the Sudan in 1965-66. Although dates and locations of work are generally given, there are very few subject titles in these notebooks. Intercalated material in the volumes may include Watt's own page markers, notes and data, and pressed plants. Some of the notebooks have soil samples smeared on the pages. The nature of Watt's research entailed observing plots of vegetation over an extended period of time. This is reflected in Watt's use of his notebooks. Many were used to record data over many years, and include subsequent reassessment and correlation of data.