8450 Surfaces 



of revolution, tangents of boundary of shadow, 

 determination. Pelz, C. Wien Ak. Sb. 79 

 (1879) (Ab. 2) 447-. 

 ruled. Pirondini, G. G. Mt. 25 (1887) 25-, 



115-. 

 , 2nd asymptotic line. Hoppe, R. Arch. 



Mth. Ps. 60 (1877) 276-. 

 , belonging to skew curve. Ciani, E. G. 



Mt. 27 (1889) 233-. 

 , class. Rouquet, V. Toul. Ac. Sc. Mm. 



7 (1895) 117-. 

 , contact. Binet, J. P. M. Par. EC. Pol. 



Cor. 2 (1809-13) 331-. 

 , and curves with constant curvature and 



torsion. Allen, A. J. C. [1882] Mess. Mth. 



12 (1883) 26-. 

 , expression for ds 2 on. Bioche, C. [1889] 



Par. S. Mth. Bll. 18 (1890) 91-. 

 , geodesic and line of striction, theorem. 



Mannheim, A. [1877] Par. S. Mth. Bll. 



6 (1878) 7-. 

 , intrinsic equations. Cesdro, E. N. A. Mth. 



9 (1890) 294-. 

 , line of striction. Nicolaldes, N. Les 



Mondes 9 (1866) 146-. 

 , given, construction. Hoppe, R. 



Arch. Mth. Ps. 11 (1892) 345-. 

 , satisfying certain conditions. 



Amigues, E. N. A. Mth. 8 (1889) 77-. 

 , orthogonal trajectories of generators. Fais, 



A. [1879] Bologna Ac. Sc. Mm. 1 (1880) 67-. 

 , paraboloid of normals. Mannheim, A. 



Par. S. Mth. Bll. 5 (1877) 190-. 

 , passing through curve. Bioche, C. N. A. 



Mth. 12 (1893) 412-. 

 , and surface envelopes. Stammer, W, 



Liege Mm. S. Sc. 1 (1866) 137-. 

 , tangential helicoid. Mannheim, A. Liouv. 



J. Mth. 4 (1878) 57-. 

 singular points. Gregory, D. F. Camb. Mth. 



J. 2 (1841) 252-. 



. Amiot, B. Brux. Mm. Cour. 4, 21 



(1846) 48 pp. 

 singularities. Maur, A. Grunert Arch. 25 



(1855) 335-. 

 , pinch points. Cayley, A. QJ. Mth. 



9 (1868) 332-. 

 skew. Catalan, E. C. [1865] Brux. Mm. 



Cour. 8, 18 (1866) (No. 5) 80 pp. 

 . Dewulf, E. Par. EC. Norm. A. 3 (1886) 



189-. 

 , asymptotic lines. Anon, (xi 19) Bll. Sc. 



Mth. As. 1 (1870) 228-. 

 helicoidal, determination of contour. Pelz, 



C. Wien Ak. Sb. 87 (1883) (Ab. 2) 473-. 

 , intrinsic equations. Cesdro, E. N. A. 



Mth. 8 (1889) 445-. 

 , lines of striction, application to illumination. 



Prochdzka. B. Casopis 18 (1889) 1-; 



Fschr. Mth. (1889) 589-. 

 , with plane line of striction. Molins, H. 



Toul. Ac. Sc. Mm. 9 (1887) 516-. 

 , principal tangent curves. Voss, A. E. 



Mth. A. 12 (1877) 485-. 



, properties. Dini, U. G. Mt. 3 (1865) 281-. 

 , property. Chome, F. (xn) Mathesis 2 



(1882) 82-. 



Congruences 8455 



skew, with same plane curve for line of stric- 

 tion and of curvature. Amigues, E. N. A. 



Mth. 14 (1895) 491-. 

 , theorems. Amigues, E. C. B. 104 (1887) 



1092-. 

 , theory. Catalan, E. C. Par. S. Phlm. 



PV. (1848) 67-. 

 , . Liiroth, J. [1866] Crelle J. 67 (1867) 



130-. 



, . Voss, A. E. Mth. A. 8 (1875) 54-. 

 , . Korteweg, D. J. N. Arch. Wisk. 3 



(*1877) 66-. 

 theory. Pellet, A. C. E. 124 (1897) 451- ; 



Par. S. Mth. Bll. 26 (1898) 138-. 

 , fundamental relations referred to movable 



trihedra. Issaly, . N. A. Mth. 19 (1900) 



49-, 240. 

 , general. Padova, E. Bologna Ac. Sc. Mm. 



10 (1889) 745-. 



, . Pellet, A. C. B. 124 (1897) 739-. 

 , infinitesimal, formulae. Frattini, G. G. 



Mt. 13 (1875) 161-. 

 , new element (Christoffel). Beltrami, E. 



Mil. I. Lomb. Ed. 2 (1869) 853-. 

 , solutions of problems depending on small 



quantities of 3rd order. Mannheim, A. C. 



E. 80 (1875) 541-, 619-. 

 transformation method. Habich, E. N. A. 



Mth. 8 (1869) 253-. 

 transformations. Enneper, A. Z. Mth. Ps. 



9 (1864) 126-. 

 triply asymptotic system, impossibility. Eisen- 



hart, L. P. [1900] N. Y. Am. Mth. S. Bll. 7 



(1901) 184-. 

 useful formulae for. Baehr, G. F. W. Grunert 



Arch. 32 (1859) 221-. 

 vectorial geometry. Genty, . As. Fr. C. E. 



(1888) (Pt. 2) 95-. 



Tangent planes, parallel, centre of mean dis- 

 tances of their points of contact. Liouville, 

 J. Liouv. J. Mth. 6 (1841) 345-. 



Terrestrial ellipsoid, theorems. Angelitti, F. 

 Nap. Ac. Pont. At. 28 (1898) No. 2, 124 pp. 



Theorem of Betti and Weingarten. Fieri, M. 

 G. Mt. 24 (1886) 290-. 



Variation of straight lines in connexion with 

 surface. Hoppe, R. Arch. Mth. Ps. 3 (1886) 

 290-. 



8455 Differential geometry of 

 congruences and other ap- 

 plications of the differential 

 calculus to elements of space. 



Congruences conjugate to systems C (K con- 

 gruences). Guichard, C. C. E. 126 (1898) 

 718-. 



which are K congruences in several man- 

 ners. Guichard, C. C. E. 126 (1898) 1011-. 



, intrinsic analysis. Cifarelli, T. G. Mt. 

 36 (1898) 145-. 



, geometry. Cesdro, E. Nap. Ed. 33 

 (1894) 141-. 



621 



