Interactive image

(Illustration by Nicholas Forder/ Future plc)

Summum dorsum Flat stone slabs were fixed into the cement neatly to create a smooth surface. The thickness of these stones was about 15 cm.

Nucleus This cement, consisting of fine sand and gravel, binded well to fix the top layer in place.

Rudus Smaller stones, of around 5 cm, were used with cement mortar to make a coarse concrete.

Statumen Large flat stones were piled evenly at the base of the road. The small gaps between stones allowed water drainage.

Gremium The ground was leveled with compact sand or dry earth to create flat foundations.

Umbones Kerb stones fitted to the edge of the road helped to bind the layers together.