Designer: J. Bacharach under supervision of Prof. Dr. L. Brill in TU München
Title in the catalog: (de) Die Rotationsflächen constanter mittlerer Krümmung nebst geodatischen Linien. b) Nodoid c) Ring des Nodoids, durch Umdrehung der Schleife entstanden
Size: 11x8 cm
Price in the catalog: 9.50 marks, 2.50 marks for the ring (1911)
Unduloid is a complete non-compact periodic rotationally symmetric surface of constant non-zero mean curvature. Model shows one period.
Profile curve of an onduloid is a locus of a focus of a branch of hyperbola rolling along a straight line (hyperbolic catenary). A hyperbolic catenary has a self-intersection (loop), which upon being rotated gives a ring (separate model) inside the outer "shell".
