4

BOOK I.

diseases to which they are more liable than workmen in other occupations,or if they do meet with them, that he himself may be able to heal them ormay see that the doctors do so. Thirdly follows Astronomy, that he mayknow the divisions of the heavens and from them judge the direction ofthe veins. Fourthly, there is the science of Surveying that he may be ableto estimate how deep a shaft should be sunk to reach the tunnel which isbeing driven to it, and to determine the limits and boundaries in theseworkings, especially in depth. Fifthly, his knowledge of Arithmetical Scienceshould be such that he may calculate the cost to be incurred in themachinery and the working of the mine. Sixthly, his learning must compriseArchitecture, that he himself may construct the various machines and timberwork required underground, or that he may be able to explain the methodof the construction to others. Next, he must have knowledge of Drawing,that he can draw plans of his machinery. Lastly, there is the Law, especiallythat dealing with metals, that he may claim his own rights, that he mayundertake the duty of giving others his opinion on legal matters, that hemay not take another man’s property and so make trouble for himself, andthat he may fulfil his obligations to others according to the law.

It is therefore necessary that those who take an interest in the methodsand precepts of mining and metallurgy should read these and others of ourbooks studiously and diligently ; or on every point they should consultexpert mining people, though they will discover few who are skilled in thewhole art. As a rule one man understands only the methods of mining,another possesses the knowledge of washing 9 , another is experienced in theart of smelting, another has a knowledge of measuring the hidden parts ofthe earth, another is skilful in the art of making machines, and finally,another is learned in mining law. But as for us, though we may not haveperfected the whole art of the discovery and preparation of metals, at leastwe can be of great assistance to persons studious in its acquisition.

But let us now approach the subject we have undertaken. Since therehas always been the greatest disagreement amongst men concerning metalsand mining, some praising, others utterly condemning them, therefore I havedecided that before imparting my instruction, I should carefully weighthe facts with a view to discovering the truth in this matter.

So I may begin with the question of utility, which is a two-fold one,for either it may be asked whether the art of mining is really profitable ornot to those who are engaged in it, or whether it is useful or not to the restof mankind. Those who think mining of no advantage to the men who followthe occupation assert, first, that scarcely one in a hundred who dig metals orother'such things derive profit therefrom; and again, that miners, because theyentrust their certain and well-established wealth to dubious and slipperyfortune, generally deceive themselves, and as a result, impoverished by

9 Lavandi —“Washing.” By this term the author includes all the operations ofsluicing, huddling, and wet concentration generally. There is no English equivalent of suchwide application, and there is some difficulty in interpretation without going further thanthe author intends. Book VIII. is devoted to the subject.