IT is intended herein: to make some brief comments on geophysical 'work in general and on the various methods, and then to refer to that branch which, perhaps, is of the greatest importance and interest to the metalliferous mining engineer, i.e., the variousmethods of electrical prospecting.The term geophysics was originally applied to those larger physical and geodetic studies and methods concerned with such purely scientific subjects as the investigation of the true figure of the earth and the determination of the stability relations resultingtherefrom. Applied geophysics and geophysical methods of prospecting are concerned primarily with the search for, and investigation of, useful mineral deposits concealed within the earth's crust and not readily detectable by the normal methods employed bythe mining geologist and prospector. The methods employed have been devised as a result of co-operation between mining men, geologists, and physicists, and, although steady progress has been made during the past 20 years or so, it is within the last four orfive years that the importance of these methods has been acknowledged by the mining world in general. Although many of these methods are still in, or have barely emerged from, the experimental stages, a steadily increasing list of important discoveries is attributable to their employment-more particularly in Europe and America than elsewhere. The various methods have each their own limitations regarding the class of work they can undertake, and no one method is capable of general application. The greatest care should be exercised in selecting the method, or methods, to be employed in any particular area, the...