Perspective machine

Timeline

• 1510: Leonardo da Vinci's Draftsman drawing an armillary sphere shows an early perspective machine in use.
• 1525: Albrecht Dürer, in his illustration Man drawing a lute, shows an artist using a perspective machine to create a drawing. The machine consists of a wooden frame with a taut string passing through it to represent the viewer's line of sight. Dürer built his second model of such a machine in the same year.
• c.1765: Scottish engineer James Watt designs a machine based on an easel, with a pantograph mechanism allowing the artist to trace an object using a sight arm and transfer the movement of the sight to a pen drawing on paper. Watt stated that his machine was based on an invention by a Mr Hurst, who lived in India.
• 1763: Philosopher Thomas Reid uses a machine to investigate his theory of perception.
• 1825: English inventor Francis Ronalds patents two perspective tracing machines. One generated an accurate drawing of an object or scene in nature and the other created a perspective view of an object from drawings of the plan and elevations. Ronalds manufactured the machines and sold several hundreds of them.