Athanasuis Kircher was a philosopher and mystic of the 17th century. In his perpetual lunar calendar showing the phases of the moon, Kircher beautifully illustrates the unity of mathematics and mysticism. By using the growth properties of the arithmetical spiral, he makes it possible to read the the hour of moonrise in each successive phase. The Selenic Shadowdial or the Process of Lunation from Ars magna lucis et umbrae engraving by Pierre Miotte (1646).   Water based ink on handmade Jute paper. 9" x 12" (22.8 x 30.4 cm) Sustainable framing available. Ships with plexiglass.