Letter from Bertrand Russell, The Millhangar, Fenshurst, Haslemere, to [Joseph] Larmor He asks Larmor for references in aid of his article on non-Euclidean geometry: on continuity and theory of numbers, on theory of surfaces, on calculus of extension, and on the theory of continuous groups. None fall within the scope of his article, but he must allude to them and he would like to refer to articles. Ten pages will suffice he thinks, as most of what is important is in Sir Robert Ball's article. 16 November 1899