Check the listing for details. Antique David White Surveyors Transom, Level, Compass. Condition: Used. Listed at 250.00 USD. The Antique David White Surveyors Transom, Level, Compass is a rare and valuable collectible for those interested in surveying equipment and engineering history. This vintage tool combines the functions of a transom (used for measuring horizontal angles), level (for determining vertical angles), and compass (for taking bearings). Manufactured by David White, a reputable brand in surveying equipment, this piece is a unique and sought-after item for collectors and enthusiasts in the field of engineering and surveying.