The power of form applied to geometric tracery : one hundred designs and their foundations resulting from one diagram
A pattern manual by the Scottish architect Robert William Billings, published in Edinburgh by W. Blackwood and Sons in 1851, deriving one hundred tracery designs from a single circle diagram for architects and ornamental draughtsmen. The plates are line engravings of compass arcs, tangent circles, radiating axes and numbered construction points, usable as geometric armatures, rosette layouts or blueprint-style line motifs.
