Cloud expansion photographs of the photoelectrons produced in hydrogen, air, and argon by means of the K[alpha] radiation of Mo show that the most probable direction of emission is the same for all three gases, and forms an angle of about 70[degrees] with the x-ray beam. These angles have been measured by means of a stereoscopic comparator specially built for the purpose. The total number of tracks measured is 443. Distribution curves plotted with number of tracks starting at a given angle with the x-ray beam against the angle show a narrower peak for hydrogen than for the argon. This qualitatively supports the view that the distribution is due to secondary scattering by the electrons in the atoms thru which the photo-electron passes and that the initial direction of emission may be constant for a definite wave length and depend only on the radiation.