DURING and since the War, a very active school of electron microscopy has grown up in the Technical University of Delft, under the direction of Dr. J. B. Le Poole. In addition to furthering the applications of the instrument, his work on its technical improvement has been of great importance, and has led to the developmetn of a commercial model by the Philips concern. In view of Dutch interest in this field, the Applied Physics Section of the Netherlands Physical Society is arranging a Conference in Electron Microscopy, which will be held at Delft during July 4-9. Its intention is to bring together specialists from other European countries and from America, to which end an international sponsoring committee has been set up. Both this and the working committee are under the presidency of Prof. H. B. Dorgelo, Technical University, Delft. A programme has been arranged, covering-all the main technical aspects and applications of the electron microscope. In each session the opening paper is to be given by an invited speaker, followed by short contributions from others. The chief topics are: image formation and contrast (E. G. Ramberg, Radio Corporation of America), preparation techniques (D. G. Drummond, Shirley Institute, Manchester), resolving power and apparatus (M. E. Haine, A.E.I. Research Laboratories, Aldermaston). The general lecture on microscopes will be given by Dr. Le Poole, and that on applications by "Prof. W. T. Astbury. Accommodation is being found in Delft and The Hague by the working committee, and party travel at reduced rates is being arranged from Great Britain. Application forms for accommodation and travel can be obtained from Dr. V. E. Cosslett, Cavendish Laboratory, Cambridge, to whom offers of contributed papers from Britain should also be sent, as early as possible.