The weak part of the Lintel is the centre of the span which may have a tendency to give way under pressure, but the wedged construction of the Arch renders the centre strong enough to bear the imposed weight.
In contrast with the Lintel, material of small size could be employed, not only stone, but brick being used in Arch construction.
No. 7. Section of Gothic Vault showing courses of stone and centering.
The Lintel, in relatively small spans, is sometimes composed of separate small stones, shaped to fit each other in the form of Joggled joints.
No. 8.
A. Lintel in one piece.