Abstract
In the late sixteenth century a number of mathematicians tried to introduce geometrical methods into surveying practice, to be based on simplified astronomical instruments, angle measurement, and triangulation. A measure of success is indicated by the acceptance of the simple theodolite, but the surveyors resisted such complex instruments as the altazimuth theodolite, recipiangle, and trigonometer. Counter-proposals, in particular the plane table, threatened to undermine the geometrical programme, but by the mid-seventeenth century a stable compromise had evolved. Among other things, the demise of the shadow square indicates that angle measurement was then part of surveying practice