What is "centrolinead"

centrolinead \cen`tro*lin"e*ad\ (s[e^]n`tr[-o]*l[i^]n"[-e]*[a^]d), n. An instrument for drawing lines through a point, or lines converging to a center.

n. An instrument for drawing lines through a point, or lines converge to a centre.

The centrolinead was invented by Peter Nicholson, a British mathematician and architect, in 1814. It was used to construct 2-point perspective drawings where one or both vanishing points existed outside the drawing board. Draftsmen could use the instrument in pairs; one for each vanishing point on each side of the station point.

Centrolineads were produced in various sizes. Typically a brass fitting clamped the wooden arms together. Fittings were produced in both right and left-handed configuration, and certain adjustable designs could be used on either side.