It is also intended as a guide to the prospector. Only an elementary knowledge Of geology and some mining experience are necessary in order to understand it. With these qualifica tions, it will materially assist him in his search for metallifcr ous mineral occurrences and, so far as simple ores are con cerned, should enable him to form some idea Of the possibili ties Of any he may find. Regarding complex ores he will, of course, need metallurgical advice in addition.