Färgerna i Torpa geometrisk jordebok Materialundersökning av en samling lantmäterikartor från 1640-talet

Abstract

The geometrical cadastre of Torpa, drawn by Swedish surveyor Nils Eriksson Njurén in 1648, was analyzed by micro-sampling Energy-dispersive X-ray (SEM-EDX) and Fourier transform infrared (FTIR) spectroscopy, in order to characterize the materials used in its production. The volume is one of the old Swedish geometrical (large-scale) cadastres that were produced during the period 1630-1655, with the purpose to gain insight of the resources of the country. The maps give detailed information about the value, extent and ownership of farms and villages together with additional information and text descriptions of the mapped features. The maps are often used in historical and archaeological research. The geometrical cadastre of Torpa consists of 146 pages in a parchment binding. The maps are hand-drawn with ink and watercolour recto and verso on paper. The aim of the study has been to give a better understanding of how the volume was made, of its history and condition, and in a wider sense to contribute to the overall knowledge of the materials and techniques used in the early Swedish cadastral maps. The investigation was carried out in two steps: First historical information was gathered and the object's physical and material attributes was examined by optical techniques, resulting in a brief structural description of the volume. Features such as watermarks in the paper, characteristics of the media, marks made by tools and signs of degradation were observed and described. Nine paint samples from different coloured fields in the book were then removed from the object and analyzed by SEMEDX and FTIR. The pictorial materials identified include traditionally used inorganic pigments such as vermillion, red lead, orpiment and verdigris as well as inorganic pigment indigo/woad. Yellow and green organic pigments were detected but could not be fully identified. The binder used was confirmed to be a natural gum. Title