Frontispiece from Athanasius Kircher's (1602-1680) 'Ars Magna Lucis Et Umbrae', (1646). Rays of light are shown bouncing off mirrors, together with heavenly bodies and clasical symbols. Kircher demonstrated that by placing a lens between a screen and a mirror which had been written on, a sharp but inverted image of the text would appear on the screen. By using a spherical water-filled flask as a condenser to concentrate the light, Kircher found that texts painted on the mirror's surface could be projected by light from a candle after dark. These demonstrations eventually resulted in the development of the magic lantern as a new form of entertainment.
© Science Museum / Science & Society Picture Library