the development of ideas previously of only academic interest into economically and commercially significant technology.
There are papers on the correction of lens aberrations and on pulsed laser holography which point out just where these techniques can be of most use. The contributions on computer sequences of holograms and on the synthetic aperture radar systems provide stimulating accounts of new and successful extensions. The papers on real-time image processing, on holographic storage, and on pattern recognition, look rather further ahead; questions still remain about the chance of realisation of some of the objectives of this work. These contributions are invaluable, however, in that the problems arising are shown to depend on future advances in certain technology (for example, in the development of suitable materials or electronic devices). Some of the papers have already been published elsewhere, and references are made to papers published after the date of the seminar. The presentation, however, is in the form of a photographic reproduction of the authors typescripts, and one cannot help wondering why the record did not appear sooner. The standard of correction of the English of the texts varies widely; in some places, misprints abound, but these are of a trivial nature, hardly likely to cause more than a moment's amusement. The ty_pescript of some of the Japanese papers appears to have been amended, presumably to clarify the meaning, but a suspicion remains that the English text does not always convey the exact meaning in the Japanese author's mind.