Conic Section Model, ca 1900. Object 1979.3002.021, Smithsonian Image DOR2013-17883. Less common are kinematic models. These devices depict mathematical concepts that involve motion. The models can be ...

Nature - Solid Geometry and Conic Sections, with Appendices on Transversals, and Harmonic Division, for the Use of Schools Elementary Geometry Skip to main content Thank you for visiting nature.com.