7240 



Quadric Surfaces. Normals. Plane Sections 



7240 



Locus of point, distances of which from 3 points 

 satisfy certain relations ( Jacobi) . Enneper,A. 

 Z. Mth. Ps. 10 (1865) 416-. 



points, distances of which from two 

 straight lines are in constant ratio. Ovidio, 

 E. d\ G. Mt. 1 (1863) 183-. 



dividing constant chords in given ratio. 



Roberts, S. QJ. Mth. 17 (1881) 280-. 



vertex of cone dividing 6 or 7 lines 

 harmonically. Chasles, M. C. R. 52 (1861) 

 1157-. 



vertices of solid 



Normals from given point. Laguerre, E. C. R. 



78 (1874) 438-. 

 to quadrics and conies. Clebsch, A. [1862] 



Crelle J. 62 (1863) 64-. 

 . Purser, F. [1866] QJ. Mth. 



8 (1867) 66-. 

 Plane through certain point, analogy to conies. 



Mandl, J. Mh. Mth. Ps. 11 (1900) 183-. 

 Rectangular trihedra, edges of which are normals 



to given quadric. Bruno, G. Tor. Ac. Sc. 



At. 15 (1879) 617-. 



paraboloid etc. , extension of Monge's theorem. 



Dubois, G. N. A. Mth. 2 (1863) 398-. 

 Metrical properties. Darboux, G. Par. S. Mth. 



fill. 2 (1874) 144-. 

 Middle points of chords through fixed points, 



locus. Crova, (Prof.) . (vi Adds.) Per- 



pignan Bll. S. Ag. Pyr. Orient. 7 (1848) 



252-. 

 , . Unferdinger, F. 



Arch. Mth. Ps. 42 (1864) 118-. 

 . , . Ende, H. am. Arch. 



Mth. Ps. 42 (1864) 358-. 



Normals to Quadrics. 



Chasles, M. Liouv. J. Mth. 8 (1843) 215-. 

 Desboves, A. H. N. A. Mth. 2 (1863) 228-. 

 Joachimsthal, F. Crelle J. 73 (1871) 207-. 

 Laguerre, E. N. A. Mth. 17 (1878) 163-. 

 Humbert, G. C. R. Ill (1890) 963-. 

 Machovec, F. Prag Sb. (1890) 1 (Mth.-Nt.) 



119-. 

 Conditions for. Pinkerton, E. H. Edinb. 



Mth. S. P. 13 (1895) 126-. 

 Ellipsoid, normals. Geiser, C. F. [1867] A. 



Mt. 1 (1867-68) 317-. 

 , . Boklen, O. N. A. Mth. 18 (1899) 



121-. 

 , making equal angles with two given 



normals. Grunert, J. A. Arch. Mth. Ps. 



47 (1867) 204-. 

 , , number from point. JoachimstJial, F. 



Crelle J. 59 (1861) 111-. 

 , shortest distance between 2 normals. Gru- 

 nert, J. A. Grunert Arch. 21 (1853) 314- ; 



38 (1862) 228-. 

 Joachimsthal 's theorem on circles and spheres 



through feet of normals. Schoute, P. H. 



Amst. Ak. Vs. 8 (1900) 744- ; Amst. Ak. P. 



2 (1900) 593-. 

 Normal surfaces to ellipsoid along an ellipse 



of principal system. Solin, J. M. [1868] 



Prag Ab. 2 (1869) 59 pp. 

 along plane sections. Koutny, E. Wien 



Ak. Sb. 75 (1877) (Ab. 2) 851-. 

 Normals and central surface of algebraic sur- 

 faces. Waelscli, E. Ac. Nt. C. N. Acta 52 



(1888) 285-. 

 quadrics. Waelscli, E. Wien 



Ak. Sb. 95 (1887) (Ab. 2) 549-; 97 (1889) 



(Ab. 2a) 583-. ' 

 from external point, simple method of 



drawing. Niemtschik, R. Wien Sb. 58 



(1868) (Ab. 2) 831-. 

 given point. Clebsch, R. F. A. (vn) 



Tortolini A. 4 (1861) 195-. 



circumscribing , quadric, locus of vertices. 



Painvin, L. N. A. Mth. 10 (1871) 337-. 



Sum of squares of normals, locus when con- 

 stant. Terquem, O. Liouv. J. Mth. 4 (1839) 

 241-. 



, . Walton, W. [1869] 



QJ. Mth. 10 (1870) 167-. 



Number of solutions of elementary questions. 



Hoitsel, . C. R. 60 (1865) 1072-. 

 Paraboloids, elliptic. Bazant, J. Fschr. Mth. 



(1899) 565. 

 , , circular sections. Babin-et, J. C. R. 



43 (1856) 453-. 

 , elliptic and hyperbolic. Colecchi, 0. 



H Progresso 22 (1839) 41-. 

 , , complanation. Schldmilch, 0. 



Grunert Arch. 11 (1848) 233-. 

 , , generation. Berard, . Ger- 



gonne A. Mth. 6 (1815-16) 122-. 

 , osculating. Olivier, T. Par. EC. Pol. J. 



cah. 25 (1837) 230- ; Liouv. J. Mth. 3 



(1838) 249-, 335-. 

 , properties. Allman, G. J. [1873] QJ. Mth. 



13 (1875) 102-. 

 of 8 straight lines. Mannheim, A. C. R. 



84 (1877) 645- ; 123 (1896) 983-. 

 , surface. B&klen, O. [1882] Arch. Mth. 



Ps. 69 (1883) 222-. 

 , vertex and principal axes. Housel, . N. 



A. Mth. 17 (1858) 223-. 

 Parameters, invariable functions. Ledent, J. 



Liege Mm. S. Sc. 3 (1873) 21-. 

 Plane enveloping sphere, property and extension 



to any surface. Ocagne, M. d'. L. Mth. S. 



P. 18 (1886-87) 361-. 



Plane Sections of Quadrics. 



Cayley, A. [1863] (vn) Ph. Mg. 27 (1864) 43-. 

 Mertens, F. Crelle J. 74 (1872) 362-. 

 Central sections, locus of foci. Le Besgue, V. 



A. N. A. Mth. 5 (1866) 444-. 

 Centre, analytical determination. Saltel, L. 



N. A. Mth. 14 (1875) 271-. 

 Circular sections. Finlay, R. Mathematician 



2 (1847) 173-. 

 . Weddle, T. Mathematician 3 (1850) 



57-. 

 . Tillot [Tillol}, J. N. A. Mth. 10 



(1851) 304-. 

 . Walton^ W. Camb. and Dubl. Mth. J. 



7 (1852) 7-. 

 . Donkin, W. F., & Spottisicoode, W. 



Crelle J. 47 (1854) 225-. 



510 



