* Proceedings Camb. Phil. Soc. 21 (1923), pp. 297–362.Google Scholar

* The symbol q. signifies with respect to.

* The curve determined by the equation f = 0 will often be referred to as the curve f.

* See (1.21).

* The equation of the order-cubic T ₁ may (cf. 2.1) be written in the form

where

and the sides (ξ= 0, η=0, ζ=0, ν=0) of the quadrilateral of reference are respectively B ₁C ₁, C ₁A ₁, A ₁B ₁, A ₀B ₀C ₀. The coordinates (ξ, η, ζ) of the four points I_A are then (±α, ±β, ±γ) and the ambiguous signs involved are those referred to in the text; while the forms C_k involve only even powers of the numbers α, β, γ, as is of course implied in the theorem (6.21).

* As in (5.24), C _{λ, k} having double contact with K _{λ, k} (λ = 0, α, β, γ).

† Any plane order-cubic, T ₁, of the T-pencil, and the apolar class-cubic, θ₁, of the θ-range, may be substituted for T₁, θ₁, respectively throughout the specification. Since i, k are independent, ∞ ² systems of sixteen conies [T] may thus be obtained.

* Malgouzou, , Nour: Annales (4), 19 (1919), p. 210.Google Scholar