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 or 

 may see that the doctors do so. Thirdly follows Astronomy, that he may 

 know the divisions of the heavens and from them judge the direction of 

 the veins. Fourthly, there is the science of Surveying that he may be able 

 to estimate how deep a shaft should be sunk to reach the tunnel which is 

 being driven to it, and to determine the limits and boundaries in these 

 workings, especially in depth. Fifthly, his knowledge of Arithmetical Science 

 should be such that he may calculate the cost to be incurred in the 

 machinery and the working of the mine. Sixthly, his learning must comprise 

 Architecture, that he himself may construct the various machines and timber 

 work required underground, or that he may be able to explain the method 

 of the construction to others. Next, he must have knowledge of Drawing, 

 that he can draw plans of his machinery. Lastly, there is the Law, especially 

 that dealing with metals, that he may claim his own rights, that he may 

 undertake the duty of giving others his opinion on legal matters, that he 

 may not take another man's property and so make trouble for himself, and 

 that he may fulfil his obligations to others according to the law. 



It is therefore necessary that those who take an interest in the methods 

 and precepts of mining and metallurgy should read these and others of our 

 books stud'ously and diligently ; or on every point they should consult 

 expert mining people, though they will discover few who are skilled in the 

 whole art. As a rule one man understands only the methods of mining, 

 another possesses the knowledge of washing', another is experienced in the 

 art of smelting, another has a knowledge of measuring the hidden parts of 

 the 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 have 

 perfected the whole art of the discovery and preparation of metals, at least 

 we can be of great assistance to persons studious in its acquisition. 



But let us now approach the subject we have undertaken. Since there 

 has always been the greatest disagreement amongst men concerning metals 

 and mining, some praising, others utterly condemning them, therefore I have 

 decided that before imparting my instruction, I should carefully weigh 

 the 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 or 

 not to those who are engaged in it, or whether it is useful or not to the rest 

 of mankind. Those who think mining of no advantage to the men who follow 

 the occupation assert, first, that scarcely one in a hundred who dig metals or 

 other such things derive profit therefrom ; and again, that miners, because they 

 entrust their certain and well-established wealth to dubious and slippery 

 fortune, generally deceive themselves, and as a result, impoverished by 



*Lavandi — "Washing." By this term the author includes all the operations of 

 sluicing, huddling, and wet concentration generally. There is no English equivalent of such 

 wide application, and there is some difficulty in interpretation without going further than 

 the author intends. Book VIII. is devoted to the subject. 



