Twelve detailed, narrative, manuscript diaries, Jan 1933-Aug 1936 and Jan 1938-Dec 1944 (with postscripts added in Jan and Sep 1945), including Pownall's time as Military Assistant Secretary, Committee of Imperial Defence, 1933-1935, Commandant, School of Artillery, Larkhill, Wiltshire, 1936-1938, Chief of General Staff, BEF (British Expeditionary Force), France, 1939-1940, Commander-in-Chief, British Forces in Northern Ireland, 1940-1941, and Chief of Staff to Supreme Allied Commander, South East Asia Command, 1943-1944, with aerial photograph of Belfast, Aug 1940, and a group photograph of the officers of South East Asia Command [1945], typescript extracts from reports, letters and typescript extract from the diary of Maj Gen Edmund Archibald Osborne, on the campaign in France, 1940. Also, printed order of service in memory of FM John Standish Surtees Prendergast Vereker, 6th Viscount Gort, 10 Apr 1946, and related newspaper cuttings. The diaries were published as Chief of Staff. The diaries of Lieutenant General Sir Henry Pownall, edited by Brian James Bond (Leo Cooper, London, 1972).

Photocopies of extracts from MacDermott's autobiography, 'An enriching life', privately printed in 1979, primarily concerning the death of his brother in France, Jan 1916, MacDermott's work in shell shop at Harland and Wolff Ltd, 1916, his experience of the Easter Rising, Dublin, Apr 1916, his military training in Belfast and the UK, 1916-1917, his service in France, Belgium and Germany, including the Battle of the Lys, Apr 1918, and the second Battle of the Marne, Jul-Aug 1918, his legal training, 1919-1921, and his reading of FM Sir Henry Wilson...his life and diaries by Sir Charles Edward Callwell (Cassell and Co, London, 1927) and Revolt in the Desert by Thomas Edward Lawrence (later Shaw) (Jonathon Cape, London, 1927) and also including a tribute by to MacDermott Lord Robert Lynd Erskine Lowry, Baron Lowry, Lord Chief Justice of Northern Ireland.