it you come to a halt. Sparavigna 2013 notes, "He illustrates the designs of musical instruments such as mechanical organs (Puerilia) and masks, keys and locks, warships, double mirrors, stoves and surgical instruments. The code contains a part dedicated to hydraulic projects, public fountains, systems of water distribution, experiments with siphons, and also alembics and alchemical vessels for two or more liquids. According to [10,6], this manuscript shows that Fontana aimed to investigate a series of devices from ancient books of mathematicians and naturalists such as Archimedes, Heron, Philo, and even Ovid and Pliny the Elder, and the Arab writers, mainly from Al-Kindi, to his contemporary artists and craftsmen." Secretum de thesauro experimentorum ymaginationis hominum In the book Secretum de thesauro experimentorum ymaginationis hominum (Secret of the treasure-room of experiments in man's imagination), written ca. 1430, Fontana described mnemonic machines, written in his cypher. At least Bellicorum instrumentorum liber and this book used a cryptographic system, described as a simple, rational cipher, based on signs without letters or numbers. It has been suggested that some illustrations slightly resemble Voynich illustrations. During this time he also met with the Count of Carmagnola. See also Johannes Trithemius References External links Bellicorum instrumentorum liber at the Bavarian State Library. Illustrations of Bellicorum instrumentorum liber at the Bavarian State Library Complete scans of Secretum de Thesauro BNF NAL 635 1395 births 1455 deaths Medieval Italian engineers 15th-century Italian physicians Venetian engineers Military technology books Italian male writers Medieval military writers Physicians from Venice 15th-century Venetian writers Venetian Renaissance humanists