Appendix Scientiam Spatii Absolute Veram Exhibens

In 1831 he published “Appendix Scientiam Spatii Absolute Veram Exhibens” (“Appendix Explaining the Absolutely True Science of Space”), a complete and consistent system of non-Euclidean geometry as an appendix to his father’s book on geometry, Tentamen Juventutem Studiosam in Elementa Matheseos Purae Introducendi (1832; “An Attempt to Introduce Studious…