Originally published in 1556, Agricola's De ReM etallica was the first book on mining to be based on field research and observation — what today would be called the "scientific approach." It was therefore the first book to offer detailed technical drawings to illustrate the various specialized techniques of the many branches of mining, and the first to provide a realistic history of mining from antiquity to the mid-sixteenth century. For almost 200 years, Agricola remained the only authoritative work in this area and by modern times it had become one of the most highly respected scientific classics of all time. A book more often referred to in literature on mining and metallurgy than any other, its Latin text prevented it from being as widely used as it might have been. In 1912, the book was translated by former President Herbert Clark Hoover and his wife. Printed in a limited edition, the work was quickly bought up by book collectors, historians, and medievalists, who had found that there was much to be learned from its pages. The book contains an unprecedented wealth of material on alluvial mining, alchemy, silver refining, smelting, surveying, timbering, nitric acid making, and hundreds of other phases of the medieval art of metallurgy. The text even covers the legal aspects of mining the use of boundary stones, forfeitures of titles, safety requirements of tunnel building in the 1500s, and so on. But the plates, perhaps more than anything else, have insured Agricola's continued importance. Brilliantly executed drawings, richly detailed, reveal a whole medieval world of machinery, industrial technique, tools, even costume and architecture. All 289 of the original woodcuts are reproduced in this reprint of the 1912 edition, offering students of the period, commercial artists, engineers, metallurgists, and even curious general readers an unforgettable picture of the first age of technology.