EHG4062 - Measured survey - Souterrain, Borgie, Sutherland

A measured survey of the souterrain at Borgie, Sutherland, was undertaken by P Humphreys and B Hiddleston in 1997. A once angled horizontal datum line was used to accommodate the curve of the souterrain, the distance from the walls, roof and floor were then measured along this line at every 0.5 metres. The detail of the entrance was drawn using a half metre drawing frame. The angle on the datum line was measured using a magnetic compass. The internal survey was related to the external survey by setting a vertical pole on the end of the internal datum line which was arranged to pass through the roof hole: external measurements were then taken in relation to this pole. <1> This survey data was updated in February 2012 by P Humphreys with the addition of further observations and a reconstruction drawing based on evidence from the site. <2>