The diaries describe Charles Pasley’s regular activities in considerable detail, especially his continued work as public examiner for the East India Company's Military Seminary, Addiscombe College, Surrey, and the experiments at the Royal Engineer Establishment, Chatham, on his decked, copper-lined pontoons. Other subjects mentioned include army organisation, railways, revisions of his books on military engineering, decimal coinage, meetings of various learned societies attended, especially the Institution of Civil Engineers, and family and personal affairs. The diaries also contain copies of some of his correspondence.