COORDINATES—CRUNODE. 
86 
Coordinates, Transformation of: i, 1-23—6, iv, 552—9, xi, 136—42; in Ency. Brit., xi, 558—61, 573—6. 
Copfaffian: the term, хш, 406. 
Coriolis, G.: motion of three bodies, iv, 541. 
Corpus: Sylvester’s theory of the, хш, 47. 
Correspondence: on cubic curves, i, 184, 190; homographic figures, i, 212; theory, vi, 263—91, x, 
259—60, xi, 482 ; in-and-circumscribed triangle, viii, 222—5; vicinal surfaces, vill, 301—8; of two 
variables, ix, 94—5, xii, 104; geometrical representation of imaginary variables, x, 316—23; con 
struction of a, xi, 38; quadric transformation between points and planes, xii, 100—1; of Cartesians, 
and generators of hyperboloid, xii, 587—9. 
Correspondence of Points: v, 542—5, vi, 22, vn, 168—70, xi, 440; two on a curve, vi, 9—13; on a 
conic, viii, 14—21; on surfaces, viii, 200—8; and lines, viii, 566. 
Cos-centre: the word, хш, 551. 
Cotes, R.: central forces, iv, 517, 586. 
Cotterill, T. : correspondence of points, vi, 22; problem of envelope and two circles, vii, 573; theorem 
of Geiser, ix, 506; goniometric problem, x, 295—7. 
Counter-barriers: the term, x, 320. 
Counter Order: the term, хш, 268. 
Couples: algebraic, i, 128—31. 
Cournot, A. A.: motion of a body, iv, 583, 586. 
Covariantive Forms and Tables: xi, 277—80; M to W of binary quintic, n, 282—309; asyzygetic, to 
degree 18, vi, 149—52; 34 concomitants of ternary cubic, xi, 342—56; of binary sextic, xi, 372—6, 
377—88; theory of tamisage, xi, 409—10. 
Covariants: the term, i, 577, 589, ii, 224, iv, 594, 605, x, 340, хш, 46; determined by differential 
equations, ii, 164—78; theory, n, 164—78; of binary cubic, n, 189, 260—2; binary quadratic, II, 189; 
binary quartic, ii, 190, 262—4; asyzygetic, n, 250 ; binary quantic, n, 269; of cubic, analogous to 
invariants of quartic, n, 553; bibliography, n, 598—601 ; of degree 6, vi, 148—53; of binary cubic, 
geometrical interpretation, vii, 332—3; the terms asyzygetic and irreducible, vn, 336; theory of 
number of irreducible, vii, 336—7; also new formulae for asyzygetic, vii, 337—40; also 23 funda 
mental, vii, 341—8; Gordan’s proof for the number, vii, 348—53; theory founded by Cayley, viii, 
xxix—xxx; his work, viii, xxx—xxxii; as transvectants, viii, 404—8; connected with an algebraical 
operation, ix, 537—42 ; derivatives of three binary qualities, x, 278—86; theorem, x, 430—1; a 
formula, xi, 122—4 ; formula and Schwarzian derivative, xi, 184—5 ; in geometry, xi, 474; Sylvester 
on, хш, 47 ; a hyperdeterminant identity, хш, 210—11; theory of derivation connected with particular 
operators, хш, 329—32; {see also Invariants, Linear Transformation, Seminvariants). 
Cox, H.: Taylor’s theorem, viii, 493. 
Cox, H., Jun.: non-Euclidian geometry, хш, 481. 
Cramer, G.: determinants, i, 63; curve classification, v, 354; transformation of plane curves, vi, 1. 
Creedy, C.: tangential of cubic, n, 558; calculations by, in, 361; elliptic motion, iv, 522, 586. 
Cremona, L.: on Steiner’s quartic surface, v, 423; general theory of correspondence, vi, 22—3; Casey’s 
equation, vi, 66—7; scrolls, vi, 327—8, vii, 245—51 ; polyzomal curves, vi, 575—6; rational trans 
formation, vii, 189, 200, 207, 222, 253—5, xi, 482, 484; theory of curve and torse, viii, 72, 76—9, 
87—91; geometric transformation, x, 611—2. 
Critic Centres {see Involution of Cubic Curves). 
Criticoids: and invariants, xii, 390 ; and reciprocants, хш, 366—7 ; of Cockle, хш, 366—7. 
Critic Points and Lines: the term, x, 311—5. 
Crofton, M, W.: polyzomal curves, vi, 507; Cartesian curves, vn, 582. 
Cross-points: the term, x, 317. 
Crunodal: the term, v, 402, 551, xi, 228. 
Crunode: defined, iv, 181, v, 295, 521, xi, 630.