The drawings in this sketchbook were made in the late 1740s while Sandby was employed by the Board of Ordinance to make maps of the Scottish Highlands. As well as observing the landscape, Sandby made a number of figure studies, including soldiers and ordinary Highland families. This portrait shows a young man dressed in military clothes who is sketching. It may be Sandby’s friend William Roy, but it has also been suggested that it might be Sandby himself. The background shows a large estate and a castle. Sandby’s other sketches of this period show a number of unidentified houses and estates, which he encountered while in the field undertaking the survey.