The correspondence includes a letter from Pope inviting Joseph Needham to attend the Congress, 20 September 1959; description of the forthcoming Persian Congress; Joseph Needham's letter of reply, declining the invitation but stressing 'we are always extremely Persia-conscious with regard to the ever-recurring question of contacts between the eastern and western ends of the Old World..', 22 October, 1959; further letter from Pope trying to pursuade Joseph Needham to attend, 30 March, 1960; letter from Joseph Needham declining, 6th April, 1960.