Published online by Cambridge University Press: 06 February 2009
Until comparatively recently, the diphthong systems of southern English accents have appeared virtually symmetrical, and such an ideally symmetrical system for the closing and centring diphthongs is shown in Figures 1 and 2. (The diphthong /ɔI/, which of course does upset the symmetry, is omitted for the sake of exposition. Historically too this omission is well-motivated, as this diphthong was a borrowing from Norman French (Gimson, 1962: 132), and still has a limited distribution (Gimson, 1962: 148).)