project, but even so de Raet continued and enough of it was completed to enable the drawing of rafts to Wolfenbüttel on the Oker and Nette. However, he had to abandon the next phase, which had planned to push through the Braunschweiger Landwehr fortifications and get as far as the city limits of Brunswick. He attempted to replace it with a plan to link the Oker to the Aller via the Aue, Erse and Fuhse, but this was successfully opposed by William the Younger, Duke of Brunswick-Lüneburg. de Raet was also put in charge of regulating the flow of the Oker and Innerste south of Wolfenbüttel in Richtung towards the Harz, which he carried out from 1574 to 1577. He built the and Julius-Staus dam in 1573, which kept the water level constant and thus enabled building materials and other goods to be transported by raft. He also collaborated with Paul Francke to modernise the defences at Schloss Wolfenbüttel, combining Italian methods such as brick with newer Dutch methods, such as using excavated soil, which was more cost-effective. In 1578 he produced a windmill and treadmill at the Silberne Schreibfeder coal mine at Julius' request. Sometime after 1577 he designed plans to regulate the flow of the Arno between Florence and the sea for Francesco I de' Medici, Grand Duke of Tuscany – this was initially at his own expense, though he was later paid 60,000 scudi for the design. Bibliography (in German) Otto von Heinemann: Herzog Julius von Braunschweig und seine Navigationspläne. In: Braunschweiger Magazin. 1898. Paul Zimmermann (Hrsg.): Jahrbuch des Geschichtsvereins für das Herzogtum Braunschweig. Zwißler, Wolfenbüttel 1903, S. 118. (archive.org) Oskar de Smedt: Wilhelm de Raet, Baumeister und Ingenieur (ca. 1537–1583). In: Friedrich Thöne (Hrsg.): Braunschweigisches Jahrbuch. Band 46, 1965, S. 147–150. digisrv-1.biblio.etc.tu-bs.de (PDF) Christian Lippelt: Raet, Wilhelm de. In: Horst-Rüdiger Jarck, Dieter Lent, etc. (ed.s): Braunschweigisches Biographisches Lexikon – 8. bis 18. Jahrhundert. Appelhans Verlag, Braunschweig 2006, , pages 572–573. Viel Steins in der Radau (PDF, S. 4) References 1530s births 1583 deaths 16th-century Dutch people Dutch engineers Hydraulic engineers Principality of Brunswick-Wolfenbüttel History of Tuscany People from 's-Hertogenbosch Year of birth uncertain