Ars Magna Lucis et Umbrae ("The Great Art of Light and Shadow") is a 1646 work by the Jesuit scholar Athanasius Kircher. It was dedicated to Ferdinand IV, King of the Romans and published in Rome by Lodovico Grignani. A second edition was published in Amsterdam in 1671 by Johann Jansson. Ars Magna was the first description published in Europe of the illumination and projection of images. The book contains the first printed illustration of Saturn and the 1671 edition also contained a description of the magic lantern. Ars magna lucis et umbrae followed soon after Kircher's work on magnetism, Magnes sive de Arte Magnetica (1641) and the title was a play on words. In his introduction Kircher notes that the word 'magna' alluded to the powers of the magnet, so that the title could also be read “The Magnetic Art of Light and Shadow”. The work was well-known for several decades. Content Ars Magna is the first of Kircher's works to follow a symbolic structure. It consists of ten books, represented as the ten strings of the instrument with which the psalmist praises the Lord in Psalm 143. The ten books also have a kabbalistic significance, betokening the ten sefirot. Kircher dealt comprehensively with many different aspects of light, including physical, astronomical, astrological and metaphysical. He discussed phenomena such as fluorescence, phosphorescence and luminescence, optics and perspective. He also described pareidolia. The work deals first with the sun, moon, stars, comets, eclipses and planets. It also discusses phenomena related to light, such as optical illusions, colour, refraction, projection and distortion. The work includes one of the first scientific on phosphorescence and the luminosity of fireflies. He devoted much care to descriptions of instruments such as sundials, moondials and mirrors that make use of light. He had written extensively on these subjects in an earlier work, the Primitiae gnomoniciae catroptricae. Kircher also discussed the "magic lantern" - he is sometimes, incorrectly, credited with inventing this device. In the section “Cosmometria Gnomonica”, Kircher set out to show how, by measuring sunlight and shadow, it was possible to measure the universe itself. He estimated the depth of the earth’s atmosphere, the distance between the moon and the earth, the diameter of the sun and its distance from the earth. The book concludes with a verse: <blockquote>"Disperge has radiis animae fulgentibus umbras Ut tua sit mea lux lux mea sit tua lux" ("Disperse