Geometry. 



179 



8090 



Mangelsdorf, Ernst. Eine ncue Ab- 

 biklimg des lincareii Strahleukom- 

 l)lexcs auf deiu Punktrauni. J)iss. 

 .Strassburg i. E. (C. Miili & Cic), IDOG, 

 (33). 23 cm. 



Martinetti, V. Sullo coijpic di to- 

 tracdri reciprocameute inscritti c cir- 

 coscritti. • Messina, Atti Ace. Pelori- 

 tana, 18, 1903-01, (13G-144). 



I gruppi di tre tetraedii 



I'un I'altro inscritti e eircoscritti. 

 Giorn. mat., Napoli, 42, 1904, (22-59). 



Morley, Frank. On two cul>ic curves 

 in triangular relation. London, Proc. 

 Math. Soc, (Ser. 2), 4, 1906, (384-392, 

 with 1 pi.). 



Neuberg, J[oseph]. Untersuchung 

 des quadratischen Unidrehungscom- 

 l)lcxes der Oeraden, deren Entfer- 

 nungen zu zwei gegebcnen Punkten 



der.Bedinsrung 



+ 



h' 



= 1 genii- 



gen. (HoUiindisch) Amste^dam, Wisk. 

 bpg., 9, [190G]. (334-336). 



Die Senlu'echten aiis den 



Punkten eines ebenen Feldes auf die 

 iiinen zugeordneten Geraden eines 

 reciprok verwandten Strahlenfeldes bil- 

 den eine Strahlenkongruenz vierter 

 Ordnung, dritter Klasse. (Hollan- 

 disch) Amsterdam, Wisk. Opg., 9, 

 1906,' (342-344). 



Stuyvaert. Sur les congruences de 

 cuhiques gaudies. Paris, C.-R. Acad, 

 sci., 141, i905, (750-752). 



Vries, Jan de. A group of com- 

 ])lexes of rays, [compounded of the 

 linear congruences having for direc- 

 trices the pairs of generatrices of a 

 rational scroll, arranged in the groups 

 of an involution I,,], whose singiilar 

 surfaces consist of a scroll and a num- 

 ber of planes. Amsterdam, Proc. Sci. 

 K. Aknd. Wet., 8, ]90(), ((562^665) 

 (English) ; Amsterdam, A'ersl. Wis. 

 Nat. Afd. K. Akad. Wet., 14, 1906, 

 (666-668) (Dutch). 



Quadratic complexes of 



revolution. [Equation, symmetrical 

 case, singular surface, bisingular points, 

 axial surfaces, particular cases, homo- 

 graphic transformation.] Amsterdam, 

 Proc. Sci. K. Akad. Wet., 9, [1906], 

 (216-221) (English) ; Amsterdam, 

 Versl. Wis. Nat. Afd. K. Akad. \\et., 

 15, [19061, (211-216) (Dutch). 



Wilczynski, E[rnest] J[ulius]. Be- 

 merkung [zu dem Aufsatz : A funda- 

 mental theorem in the theory of ruled 

 surfaces.] Math. Ann., Leipzig, 58, 

 1904, (584). 



Zindler, Konrad. Zm- Differential- 

 geometrie der Linienkomplcxe. Mon- 

 Hfte Math. Phys., Wicn, 17, 1906, 

 (287-294). 



• Die Entwicklung und der 



gegenwartige Stand der differentiellen 

 Liniengeometric. Jahresber. D. Math- 

 Ver., Leipzig, 15, 1906, (185-213). 



Liniengeometrie mit Au- 



wcndungen. Bd 2. (Samnilung Schu- 

 bert. 51.) Leipzig (G. J. GiJschen), 

 1906, (VII + 252). '20 cm. 



8090 SYSTEMS (LINEAR, AND 

 NOT LINEAR) OF CURVES 

 AND SURFACES. 



Berzolari, Luigi. Allgemeine Theorie 

 der hoheren ebenen algebraischen 

 Kurven. [Eneyklopadie d. mathem. 

 Wissenschaften. Ed 3, Abt. 64.] Leip- 

 zig, 1906, (313-455). 



Eisenhart, L^uther] P[fahler]. As- 

 sociate surfaces. Math. Ann., Leipzig, 

 62, 1906, (504-538). 



Peirce, B[enjamin] O[sgood]. On 

 generalized space differentiation of 

 the second order. Boston, Mass., 

 Proc. Amer. Acad. Arts Sci., 39, 1904, 

 ([375J-386). Separate. 23 cm. 



Schuh, F[rederik]. On the locus of 

 the i)airs of common ])oints and the 

 envolope of the common chords of 

 the curves of three pencils. 1st part. 

 [Order of the locus. Multij)le points. 

 Class of the envelope.] Amsterdam, 

 Proc. Sci. K. Akad. Wet., 9, [1906], 

 (424-434) (English) ; Amsterdam, 

 Versl. Wis. Nat. Afd. K. Akad. Wet., 

 15, [1906], (412-422) (Dutch). 



Vries, Jan de. Some properties of 

 pencils of algebraic curves [concerning 

 the locus of the m"' tangential points 

 of one of the basepoints, the number 

 of ciu'ves with an inflection of which 

 the tangent touches the curve in one 

 ])oint more, the three-fold tangents, 

 the four-point tangents, the curve of 

 inllections and the bitangential curve.] 



