Hartmann writes sundial and astrolabe treatise In 1518, German instrument maker and manufacturer Georg Hartmann began writing his practical treatise Hartmann’s Practika: A manual for making sundials and astrolabes with the compass and rule, which he completed in 1528. Although the manuscript was never published, it has survived to the present. Recently, researcher John Lamprey rearranged and edited Hartmann's draft into seven chapters (‘books’) according to the type of instrument described.[1] End Note [1] Hartmann 2002, translated and edited by Lamprey. Reference Hartmann, G. 2002. Hartmann’s Practika: A manual for making sundials and astrolabes with the compass and rule (Translated and edited by J. Lamprey). USA: J. Lamprey. Karr Schmidt, S. 2018. Interactive and Sculptural Printmaking in the Renaissance (Brill’s Studies in Intellectual History, Volume 270/21). Leiden: Brill. Image Credit Georg Hartmann, Astrolabe, 1532, Museum number: 1871,1115.3. The British Museum © The Trustees of the British Museum, CC BY-NC-SA 4.0, https://www.britishmuseum.org/collection/object/H_1871-1115-3