AT a meeting of the Physical Society held on January 31, the results of several recent researches by radar and radio methods into ionospheric ionization effects produced by meteors were described. The E-layer of the ionosphere, which occurs in a region around a height of 100 km., is characterized by one regular and two irregular forms of ionization. The regular ionization, the normal E-layer, is known to be controlled in a uniform manner by ultra-violet radiation from the sun. The problems of the origin and control of the irregular forms, which for many years have been largely a matter for speculation, were the subject of the papers presented at the meeting. In 1932, A. M. Skellett1 in the United States had suggested that meteors were an important agency in producing irregular ionospheric ionization, and with J. P. Schafer and W. M. Goodall2 he gave experimental evidence of certain increases in ionization which could be associated with meteors. Although the experimental data which accrued in subsequent years appeared on the whole to support Skellett's suggestions, it is only by the recent work, particularly in Great Britain, that a more comprehensive account of the complex characteristics of the irregular ionization in relation to the meteoric theory could be given.