ABSTRACT
ABSTRACT: Electrical and magnetic methods for archaeological surveying have reached nowadays such a high level of efficiency in terms of speed and legibility of maps that other methods often appear to be of less interest. This is the case for electromagnetic (E.M.) methods despite their unique ability for detection of specific targets or under special circumstances. These methods can be disregarded for several reasons among which the complexity of theoretical aspects, the large variety of available instruments with not well-known specific abilities, a rather slow rate of data collection, etc. must be recalled. Several previous papers (Taggagh, 1990) have already dealt with the theoretical aspects which can also be found, by the same author, in this issue. I have myself presented almost at the same time (Hesse, 1991) a kind of classification of the instruments according to their shape, size, frequency or emitted signal. This will not be given again here in order to emphasise some historical aspects and case histories of significant interest.
