work / gadgets

rorik smith, three legged, compass, dividers, proportional, cubic, perpendicular
rorik smith, tonal slide rule, geometric, wash,
Rorik Smith, Harmonic, Aspect ratio, Musical Interval, Proportional, Rectangle, Curves,

Useful object
mixed media

dimensions variable
Rorik Smith, 2012



William Ford Stanley (1829-1909) describes in the preface to his descriptive treatise on mathematical drawing instruments 'a very silly triangular compass' which through successive reinterpretation had lost all of its moveable parts. 

The design of this useful object differs from standard three legged compasses, of the horizontal or hinged pattern, being closer to proportional dividers.

Tonal Syllogism
oil on hardwood ply

330 x 222mm

​Rorik Smith, 2012​



Towards an equal-temperament tonal scale. The composition is conceived to address the uneven distribution of tone across a geometric mixing series, by allowing the middle values to be identified by eye in a series of inter related propositions.

Tonal Slide Rule, Duplex pattern,  Geometric series 1:1 by vol.

Acrylic ink, adhesive on board

Rorik Smith, 2011



Device enabling direct value comparison from a set palette. A practical slide rule produced independently of  Phillip A. Friedell's tonal slide rule (1940) which was aimed at principally at photographers, and NASAs tonal slide rule (1966) which was devised to calculate the resulting tone of colours reproduced in black and white.