Centrolinead

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.