"It is not less certain that monuments and remains of antiquity, other than literary, have a just claim to be considered as indirect sources for the same historical result."-Christian Thomsen, Guide to Northern ArcheologyGuide to Northern Archeology (1848) by Christian Thomsen is a comparative history of craftsmanship and technology. Instead of considering the authenticity of individual objects, however, Thomsen looked at the way objects can define the ages of prehistory (stone, bronze, and iron) and he argued for the value of objects as historical sources. The purpose of his book was to explain the comparative methodology he had developed as the Curator of the National Museum of Denmark, while giving credit to the support he received from the Royal Society of Northern Archeology by taking their case to a wider European scholarly audience.