"Stiles [W S] -[18th] Th[omas] Young Oration" Photocopy of the 18th Thomas Young Oration "The Basic Data of Colour-Matching" by W S Stiles, a lecture delivered on 25 February 1955, published in 'Physical Society Year Book', (London: Physical Society, 1955). Also includes a page showing figure by Stiles and Crawford of the liminal brightness increment, a sheet of tracing paper with figure and notes by Smith, and a letter from George R Price to W S Stiles, 9 March 1964, asking for more information on blue-green degeneracy in the blue-violet region from Stiles' C.I.E. "Interim Report" in 1955. 1955