INTO THE PAST BY AEROPLANE

Hokitika Guardian, 21 September 1929, Page 6

INTO THE PAST BY AEROPLANE

(By an Archaeologist in “Daily Mail.”)

Studied from the ground, a field may appear quite featureless. Photograph it from a height of five or six thousand feet, and the sites of old tombs or buildings or fortifications stand out with quite startling clearness. ■

Air photography for ' archaeological purposes was first used in 1922. Since then so many valuable discoveries have been made that it has become quite usual to call in a flying cameraman before embarking on any work of excavation. But there is, as Mr 0. G. S. .Crawford, the leading authority, points out, so text-book authe subject, and this newest of research methods is still unfamiliar to the public and even to. many archaeologists. In his latest number (new series, No. 12) of the Ordnance Survey Professional Papers Mr Crawford explains very clearly 'the principles on which the air explorer works. Briefly, markings on air photographs fall into three classes: (1) Shadows produced by inequalities on the surface, such as a mound or a ditch: (2) tone contrasts produced by disturbance of soil or the arrangement of stones in wall or foundations; (3) tone contrasts due to the introduction of different constituents in the soil.

The photography of shadow-sites is extremely tricky. It is not sufficient merely to photograph the site—unless the right time and angle be selected the results unay be nil. How effectively the camera can be made to reveal the past that has so long lain dead and buried may be seen from Mr Crawford’s photograph of a field near Grately, in Hampshire. The largest group of rings in the photograph represent a disc-barrow under plough. It is one of a row of six, the others being hidden by trees. Other remarkable photographs presented by Mr Crawford show a long since forgotten / Homan road, the ancient earthworks of Stonehenge Avenue, burial, pits, and many other survivals from antiquity. As evidence of the uncanny power of the camera, Mr Crawford mentions the fact that a picture taken from a height of 10,000 feet revealed For the first time the prehistoric, 4ft. Sin. cart tracks of Malta. __ Only the fringe of the subject has yet been touched. Some of the richest fields for,the archaeologist in this country, such as, Kent, East Anglia, the woods of Lincolnshire and Yorkshire. Hadrian’s Wall, and Dartmoor, with its prehistoric stone villages, have never been . explored from the air. When they are it will be possible to reconstruct, more clearly than hitherto, the life of the primitive peoples who walked this land befoie the dawn of • history; ,•