Inca builders at Machu Picchu National Archaeological Park

Knowledge about the Inca measurement system is based on information from the colonial chronicles and modern studies of the 16th-century Quechua dictionaries. Based on those texts, we can presume that the Incas used an anthropometric system of measurement adopted from the proportions of the human body. Using cosine quantogram analysis and statistical verification, it is possible to verify the existence of the measurement system used by the Inca architects. For this purpose, a measurement series of architectural and water infrastructure elements were collected from 3D point cloud of the Chachabamba and Machu Picchu settlements in Machupicchu National Archaeological Park.     

Laboratory evidence of the use of metal tools at Machu Picchu (Peru) and environs

An interpretation of use-wear marks on metal artifacts is developed from the principles of metal cutting and brittle fracture and applied to surficial markings and microstructural damage on bronze tools from Machu Picchu and environs. Most of the tools have blunt edges, relatively low tin contents, and were not work hardened before use; they appear to have been designed for work that involved breaking chips from hard, brittle material. Use-wear marks on these tools are interpreted as due to sliding contacts and impacts with rock. One tool with a relatively sharp edge has a higher alloy content than those with blunt edges and has been work hardened; it appears to have been designed for cutting wood and use-wear markings suggest it was so used. A long bronze bar carries markings that suggest use by stonemasons. Many of the tools are broken and study of their microstructures shows that the bronze used has poor mechanical properties because of porosity and bands of sulphide inclusions.