In his section on the magic lantern, Zahn acknowledges his debt to Kircher, referring to Kircher’s book and to Schott’s saying “the projection of images of objects was announced in a wonderful manner by Kircher.” He also knew de Chales’ work. But he showed that an improvement could be made.
Zahn showed a complete magic lantern, or Thaumaturga Lantern (names originated by Kircher) or Megalographica Lantern (Great-writing), because even little figures and images can appear life-like in size. The system was complete: reflecting mirror to focus the light, a lamp as the light source and two projection lenses forming the projection system.
Zahn wrote, “Very great wonders are presented and set forth in the magic lantern including the projection of light and curious images.” He proves himself a showman by saying the purpose is to create “the greatest admiration and enjoyment of those looking on.”
The regular magic lantern was, he said, “already well known.” He developed some very ingenious improvements, including table model projectors which set the pattern right to the end of the 19th century. All that was later added was improved light sources including, finally, electric light. (Illustrations facing [page 64].)
Zahn for his theatre shows described how images could be projected even under water. He stressed the importance of concealing the projector in a separate room so that the audience would not know the source of the magical vision.
In one model of the magic lantern Zahn explained how the glass slides could be mounted on a circular disk which could be revolved in front of the magic lantern lens. In other words, he took the disk shown by Kircher and combined it with Kircher’s projector. But Zahn’s modification was the dominant pattern used by later experimenters, just before the dawn of the motion picture as we know it. The first projector to show “motion pictures” from hand-drawn slides was invented about 1851 by Franz von Uchatius and looked very similar to this model of Zahn.
Zahn had also many curious applications, including the use of the magic lantern to tell time or rather to project the correct time on a great “clock” on the wall. Another application was the use of the lantern, connected with a wind vane atop the structure to show the direction the wind was blowing at the particular instant. (Illustration facing [page 65].)
J. Kunckelius, who wrote on the Glass Art, is credited by Zahn with developing a good ink or paint to be used on the glass for the magic lantern slides. This information was passed on by him to his readers. From Kircher’s day until the invention of film and its use in photography in the latter part of the 19th century, glass slides formed the physical picture supports for practically every kind of a magic shadow show.
Kircher’s magic lantern was established on a scientific basis in the English-speaking world by the writing of William Molyneux, a citizen of Dublin. Molyneux became an Irish patriot by taking a stand against the contended right of the English Parliament to rule Irishmen. He was a leader in the constitutional struggle for Irish autonomy in the early part of the 18th century.
Molyneux, a professor at Trinity College, Dublin, included his treatment of the magic lantern in his Dioptrica Nova, which the censor passed on June 4, 1690 with the note, “I think this book is fit to be printed.” But it was not published until two years later. Molyneux, as other pioneers in this art-science, had his period of exile. He wrote in Dioptrica Nova, “the present distractions of our miserable country have separated me and my books.”