Note 606 — CANTO XXII.
James Romanes Sibbald translation
The ridge: Not the crown of the great rocky barrier between the Fifth and the Sixth Bolgias, for it is not on that the devils are standing; neither are they allowed to pass over it (Inf. xxiii. 55). We are to figure them to ourselves as standing on a ledge running between the fosse and the foot of the enclosing rocky steep—a pathway continued under the bridges and all round the Bolgia for their convenience as guardians of it. The bank adjoining the pitch will serve as a screen for the sinner if the demons retire to the other side of this ledge.