``Knowledge gained by experience'': Olaus Henrici -- engineer, geometer and maker of mathematical models (Q2034536)

The paper is devoted to the German mathematician Olaus Henrici (1840--1918), in particular to the geometrical side of his work. While working at University College he became an active promoter of pure geometry and a producer of models of surfaces. The author attempts to answer the following questions: What prompted Henrici's interest in models? To what extent was he involved in the physical process of production? How did he use them? How were the models received? To answer these questions the author is setting the problem into the context of Henrici's career and arguing that his interdisciplinary background was a key factor in his success as a creator of models.