Method of construction used for the roofs of some tombs. It involves laying stones in successive layers that each lean slightly into the centre so that they form a cone, They are then capped with a heavy slab of stone.
Successive projecting courses of brickwork
A series of projections, each stepped out further than the one below it; most often found on brick walls and chimney stacks.
(2) -- an arch consisting of architectural members projecting ourward from a wall and bearing the weight of the next course above it. Each course projects slightly beyond the one below. (Biers, 335)