1st Internship of Jacoba H. Hessels4th Internship of Johannes Ch. ter Haar1st Internship of Charles Francois de Kip2nd Internship of Pierre de Keijzer1st Internship of Bastiaan Jean Polak1st Internship of Jan van Rijn5e Internship of Johannes van Rijn1st Internship of Christiaan Tak1st Internship of Christiaan Willem Wulff1st Internship of Joseph de Vries1st Internship of Betje Walvis2nd Internship of David Zwaap