This analysis emphasizing co-occurrence and systematic attention to archaeological context allowed Thomsen to build a chronological framework of the materials in the collection and to classify new finds in relation to the established chronology, even without much knowledge of its provenience. In this way, Thomsen's system was a true chronological system rather than an evolutionary or technological system. His chronology was established by 1825, and visitors to the museum were instructed in his methods. Thomsen also published journal articles and pamphlets in which he emphasized the importance of the find circumstances for later interpretation and dating. Finally, in 1836, he published the illustrated monograph "Guide to Northern Antiquity", in which he described his chronology together with comments about which things occurred together in finds.