Air Reconnaissance of North Britain

The purpose of this paper is to review discoveries made by air reconnaissance during the five summers 1945-9 in the Roman military districts of Northern Britain. Most of the sites described were revealed by differences in the colour or growth of vegetation above them, and during this period the exceptional drought of 1949 gave unusually clear definition, covering much of the material now under review. The cereal crops in particular responded so sensitively to buried features as to reveal not merely the outline of buildings, but finer details such as buttresses to a wall, or floors in stone or concrete. Even in pasture, the Military Way behind Hadrian's Wall could be seen for miles together as a ribbon of parched grass (pl. v); and, most remarkable of all, the foundation-trenches of timber buildings in the legionary fortress at Inchtuthill appeared as thin green lines in the parched surface (pl. viii, 2). Such conditions occur rarely; but even in a wet summer carefully planned air reconnaissance will afford plenty of information.