FIEDLER-FRESNEL. 
98 
Fiedler, W. : symmetric functions, n, 602. 
Figures: for Pascal’s theorem, vi, 116—23; mechanical construction of conformable, x, 406; use of 
arabic, xi, 446. 
Finite Differences : formulae in, in, 132—5, xii, 412—5 ; electricity on spherical surfaces, iv, 92—8, 
99—107 ; theorem and demonstration, iv, 262—4 ; general equation of differences of second order, 
x, 47—9 ; Stirling’s theorem, x, 267—8 ; table of, xi, 144—7. 
Finite Groups (see Groups). 
Finiteness : of concomitant system of quantic, vii, 334, xi, 272—80. 
First Kind: of Abelian integrals, xii, 408—11. 
First Order: of differential equations, xii, 432—41; (see also Differential Equations). 
Five-dimensional Geometry : ix, 79 ; (see also Hypergeometry). 
Five-pointic Contact : conic of, iv, 207—39. 
Flat : the term in covariants, vm, 406—8. 
Flat-cone : the term, vm, 102. 
Flecnodal Curve: vi, 342; and torse, vi, 345, 582—5. 
Flecnode : defined, n, 28—32. 
Fleflecnodal Planes : of a surface, x, 262—4. 
Fleflecnode : defined, n, 28—32, ix, 264; of curve in transformation of elliptic functions, ix, 170—1. 
Flex : the term, v, 521. 
Flexure of Skew Surface: xi, 317—22 ; (see also Surfaces). 
Floquet, G. : linear differential equations, xii, 394, 402. 
Fluctuating Functions : addition to Lord Rayleigh’s paper, ix, 19—20. 
Fluxions : and Landen, xi, 583. 
Focals : of a quadric surface, xm, 51—4. 
Foci: of conics, iv, 505—9, vu, 1—4, 571; theory of, vi, 515—34; and antifoci, problem and solution, 
vu, 567 ; locus of, problem and solution, vu, 568. 
Focus: the term, vi, 515, ix, 552, xi, 481. 
Foot : non-Euclidian geometry, xm, 483—4. 
Forcenex, D. de : multiple algebra, xii, 466. 
Forces: equilibrium of, v, 540—1, vu, 91—5; general equation of virtual velocities, ix, 205—8; re 
sultant, x, 589 ; (see also Dynamics). 
Forms: cubic, hi, 9—12; quadratic, hi, 11—12; theory, xi, 604—9. 
Formulae: Jacobi’s canonical, for disturbed motion, hi, 76—7; in finite differences, m, 132—5; for 
differentiation, iv, 135—49; distances of point, and tactions, iv, 510—2; signification of elementary 
one in solid geometry, v, 498—9 ; integrals for intersections of line and conic, v, 500—4 ; canonical 
form of qualities, vi, 153—4; of two sets each of four concyclic points, vi, 509—11, 512—5; focal, 
and polyzomal curves, vi, 547, 549; of de Jonquières, vu, 41—3; transformation of coordinates, 
vu, 95—6, 97—8; geodesic lines on ellipsoid, vu, 501—3, 507—10; trigonometric, xii, 108. 
Forsyth, A. R. : biographical notice of Cayley, vm, ix—xliv ; addition of elliptic functions, xii, 294. 
Foucault, J. B. L. : the earth’s rotation, iv, 535, 536, 5S8. 
Fouché, M. : polyhedra, iv, 609. 
F ourier, J. B. J. : theorem as to roots of equations, x, 5 ; theory of equations, xi, 500 ; (see also 
Newton-Fourier Theorem). 
Fourth Dimension : Cayley on, vm, xxxiii—v. 
Fraction-Theorem: Jacobi’s, xii, 123—5. 
Français, J. F. : imaginaries, xii, 468. 
Franklin, F.: qualities, xm, 47. 
Fresnel, A. J. : wave-surface, iv, 420, xi, 449 ; wave and tetrahedroid surfaces, x, 252 ; Sylvester 
on the optical theory of, xm, 44.