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.” In the introduction Molyneux pointed out that up to then there was nothing written in the English language on that part of mathematics and, he said, “I am sure there are many ingenious Heads, great Geometers, and Masters in Mathematics, who are not so well skilled in Latin.” And certainly Molyneux was right, for the use of the modern languages was expanding constantly in that period. Molyneux had a low regard for Zahn, whom he called “a blind transcriber from others” and asserted that he copied the errors of de Chales. An early section of the book was “On the Representation of outward objects in a Dark Chamber; by a Convex Glass.” This was a modified version of the natural camera, first set down carefully by da Vinci and dating back to Roger Bacon.