The Sienese engineers

The manuscripts by 15th-century Italian engineers show their attempts to apply the concept of perpetual motion to operating machines. In his De ingeneis, the Sienese Mariano di Jacopo, known as Taccola (1381-ca. 1458), describes the overbalanced wheel with articulated arms depicted by Honnecourt and in Arab manuscripts. He also provides diagrams of overbalanced wheels and of what appears to be a wheel with moving arms and buckets for excavation. Another Sienese engineer, Francesco di Giorgio (1439-1501), explores the topic of a recirculation mill. He draws a hydraulic motor connected to a piston pump or an Archimedes’ screw that was supposed to be powered by the force of the falling water raised by the motor itself.

Mariano di Iacopo known as Taccola, De ingeneis I-II - Cod. Lat. Monacensis 197 II (BSBM), f. 58r - Perpetual wheel with articulated arms
Mariano di Iacopo known as Taccola
De ingeneis I-II
Munich, Bayerische Staatsbibliothek, Cod. Lat. Monacensis 197 II, f. 58r
Mariano di Jacopo detto Taccola, De ingeneis I-II, Perpetual overbalanced wheel
Mariano di Jacopo known as Taccola
De ingeneis I-II
Munich, Bayerische Staatsbibliothek, Codex Latinus Monacensis 197, pt. II, f. 69v
Francesco di Giorgio Martini, Trattato di architettura I - Ms. Ashburnham 361 (BML), f. 36r - Recirculation mills
Francesco di Giorgio Martini
Trattato di architettura I
Florence, Biblioteca Medicea Laurenziana. Ms. Ashburnham 361, f. 36r
Francesco di Giorgio Martini, Notebook,
Francesco di Giorgio Martini
Vatican City, Biblioteca Apostolica Vaticana, Codice Vat. Urb. lat. 1757, f. 147v