Photocopies of correspondence and photographs, taken from five albums, relating to Sclater's career, 1898-1927, including letter from FM Sir (Henry) Evelyn Wood, Adjutant General to the Forces, confirming Sclater's appointment as Bde Maj, Aldershot, 1898; seventeen copies of photographs and nine sketch maps relating to the Second Boer War, South Africa, 1899-1902, including photographs of Bloemfontein and Brandfort, Orange Free State, and sketch maps of the Battles of Modder River, Nov 1899 and Paardeberg Drift, Feb 1900; two photographs of the 13 pounder Quick Fire gun, newly issued to the Royal Horse Artillery, 1904; letter from Lt Col Rt Hon Arthur John Bigge, 1st Baron Stamfordham, thanking Sclater for congratulatory letter on the award of a peerage to Stamfordham, 1911; three photographs of Indian Army sepoys, 1912; correspondence, 1912- 1917, including letters relating to recruitment, military inspections and the availability of manpower from FM Sir John Denton Pinkstone French, Commander-in-Chief, Home Forces, Feb 1917, Gen Sir (Henry Macleod) Leslie Rundle, General Officer Commanding-in-Chief, Eastern Command, Feb-May 1916, and Lt Gen Sir (Cecil Frederick) Nevil Macready, Adjutant General to the Forces, Jul 1917; letter to Slater from Gen Sir (Francis) Reginald Wingate, relating to riots in Egypt, Jun 1920; letter to Sclater from Lt Gen Sir George Fletcher MacMunn, Quartermaster General, India, dated Jun 1921, relating to the political and military situation in India, particularly in the aftermath of the massacre of 479 Indian civilians by troops of the Indian Army, commanded by Brig Gen Reginald Edward Harry Dyer, Amritsar, Punjab, Apr 1919; printed obituary of Sclater [1927].

Papers relating to his life and career, 1896-1902, 1908-1918, principally comprising letters to his family, 1896-1902, notably describing his service in operations in Orange Free State and Transvaal, South Africa, 1899-1900; notebook relating to his service in South Africa, 1899-1902, containing copies of brigade and divisional orders, notes on horses health, lists of men killed and financial accounts; 'Notes from beleaguered Kimberley', an account of the siege and relief of Kimberley, Feb 1900, by one of his colleagues, [1900]; letters to his wife, 1913-1917, notably describing his service in the UK, 1914-1917, and on the Western Front, 1917; letters to Poore's wife from Lt Col William Brooksbank Garnett, Commanding Officer, 2nd Bn, Royal Welch Fusiliers, 1917-1918, chiefly concerning the circumstances of Poore's death; army message book containing notes on explosives, 1917; photographs of Poore, 1882-1917. Family papers, 1869-1879, 1893, 1899-1979, notably including papers relating to Poore's wife, Mrs Lorne Margery Poore (née Dennistoun), 1869-1879, 1899-1979; correspondence with his sister, Nina Hamilton, wife of Duke of Hamilton, concerning Poore's management of a suspense account established to provide for the Hamilton's children, 1904-1916.

Papers relating to his service in West Africa, 1897, comprising his diary, 1897; glass lantern slides, 1897. Papers relating to his service in South Africa, 1899-1901, notably including diary, Dec 1899-Jun 1900, describing operations in Orange Free State and Transvaal, Dec 1899-Jun 1900; letter books containing transcriptions of letters [to his family] describing operations in Orange Free State, Transvaal and Cape Province, Dec 1899-Sep 1901.