Personal correspondence: P-Q Correspondents include: Prof FA Paneth (Durham University); S Pankow; W Pauli (Physikalisches Institut, Zurich); George B Pegram (Columbia University, New York); Prof Rudolf Peierls; Penguin Books Ltd; WG Penney (Imperial College, London); MW Perrin; Philips, Eindhoven; GL Pickard; E Pietsch; M Pirani; Max Planck; HH Plasket; Dr RW Pohl; M Polanyi (Manchester University); HC Pollock (General Electric Company); P Pringsheim (Chicago University); MHL Pryce (Trinity College, Cambridge); EM Purcell (Harvard University) and Dr Quelle c.1924-1956