Doric Entablatures
The Doric cornice is three-quarters of a diameter in height and one diameter in projection from the face of the frieze, which should always be in vertical alignment with the architrave.
It is convenient to divide the cornice height into three. The upper third consists of a crowning cavetto moulding, supported by a cyma reversa, under which is a facia or corona, in turn supported by a dentil course. The lower third should be taken as the centre of the dentil course, and if the height from the top of the cavetto to the underside of the corona be bisected, the point of bisection should fall in the centre of the intervening reversa.