Center of involution, [141], [142]
Center of perspectivity, [8]
Central conic, [120]
Chasles (1793-1880), [168], [179], [180], 184
Circle, [21], [73], [80], [145], [146], [147]
Circular involution, [147], [149], [150], 151
Circular points, [146]
Class of a curve, [183]
Classification of conics, [110]
Collineation, [175]