Camera obscura, 1646.
© Science Museum / Science & Society Picture Library
Plate taken from 'Ars Magna Lucis Et Umbrae', published in 1646 by Athanasius Kircher (1602-1680). 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 birth of the magic lantern.