The palette

Sandstone, smooth sandstone and cut sandstone mixed block by block for rusticated masonry; cut sandstone and smooth sandstone alternating in the voussoirs; smooth sandstone stairs and slabs for the cornices, impost ledges, keystones and the cutwaters' caps; sandstone stairs for bosses and crumbled stones; calcite for the lime deposits lining the channel; water in the open channel at the break.

Techniques

• Tiers set back
• Rough ashlar
• Arches to half a block
• A broken end
• Cutwaters upstream

The steps

1. Foundations and the cutwaters
2. Lower tier: the piers
3. Lower tier: six great arches
4. Bosses and the first cornice
5. Middle tier: piers
6. Middle tier: arches
7. Second cornice
8. Top tier: the arcade of small arches
9. The water channel, lined with lime
10. Cover slabs
11. Fallen stones of the broken end

How each technique is done and every step explained, in 3D: Learn (members).

Learn it in 3D, step by step