40.0 MB (5.2 MB compressed)
3010 x 4650 pixels
25.4 x 39.4 cm ⏐ 10.0 x 15.5 in (300dpi)
NEW YORK PUBLIC LIBRARY / SCIENCE SOURCE / SCIENCE PHOTO LIBRARY NEW YORK PUBLIC LIBRARY / SCIENCE SOURCE / SCIENCE PHOTO LIBRARY
Woodcut from Agricola's, De Re Metallica. Triangulation applied to a tunnel being driven to meet a shaft. HDE is a cord suspended over the shaft, HFG is a second cord connecting to the mouth of the tunnel, and KL is a third cord to help establish the triangle. This provides a ratio for determining the tunnel's length. Georgius Agricola (1494-1555) was a German scholar known as the father of mineralogy. His book De Re Metallica, published in 1556, was a treatise on mining and extractive metallurgy, illustrated with woodcuts illustrating processes to extract ores from the ground and metal from the ore, and the many uses of water mills in mining. Agricola described and illustrated how ore veins occur in and on the ground, making the work an early contribution to the developing science of geology. It was also an important chemistry text for the period and is significant in the history of chemistry. This image has been colour enhanced.
Model release not required. Property release not required.