No clue is given by Kircher to the exact date he invented the magic projection lantern. But it was probably not long before he finished the book in 1644 or 1645. Kircher dedicated his thick quarto volume, which was handsomely published by Herman Scheus at the press of Ludovici Grignani in Rome, to Archduke Ferdinand III, the Holy Roman Emperor, King of Hungary, King of Bohemia and King of the Romans. Hence, knowledge of the screen first appeared in print under very distinguished patronage. The title page explained that the great art of light and shadow had been “digested” into ten books “in which the wonderful powers of light and shadow in the world and even in the natural universe are shown and new forms for exhibiting the various earthly uses are explained.” The Emperor wrote a foreword and this was followed by an introduction of Kircher “to the reader.” Kircher spoke of the earlier use of light and shadow by the necromancers to deceive, but pointed out that his developments were for “public use, or a means of private recreation.” Introductory material also included several odes about the subject and the author, as well as the necessary ecclesiastical approvals. The first nine books, or long sections, of _Ars Magna Lucis et Umbrae_ include such diverse topics as the following: Light, reflection, images, the speaking tube, the structure of the eye, sketching devices, the art of painting, geometrical patterns, clocks, the nature of reflected light, refraction and means of measuring the earth. The section which is of special interest in the story of magic shadows is the tenth--it gives the title to the whole work. The sub-title of the chapter is, “Wonders of light and shadow, in which is considered the more hidden effects of light and shadow and various applications.” In the preface to the section Kircher wrote “in this, as in our other research, we have believed that the results of our important experiments should be made public.” “That risk is taken,” he continued, “for the purpose of preventing the curious readers from being defrauded of time and money by those who sell imitation devices, for many have provided wondrous, rare, marvelous and unknown things and others have sold so much bunk.” The first section of the all-important tenth chapter discussed magic clocks and sun-dials; the second, the _camera obscura_ or “dark chamber,” lenses, telescopes, other optical devices. In the third section there appears the magic lantern. The section is called, “Magia Catoptrica, or concerning the wondrous exhibition of things by the use of a mirror.” _Catoptron_ in Greek means “mirror.” Kircher wrote, “Magia catoptrica is nothing else but the method of exhibiting through the means of mirrors hidden things which seem to be outside the scope of the human mind.” Ancient authorities who had made contributions to this art-science were mentioned by Kircher.