Et si tofus erit aut saxum, in suo sibi canalis excidatur, sin autem terrenum aut harenosum erit, solum et parietes cum camara in specu struantur et ita perducatur.
If the formation of the earth is of tufa or stone, the channel may be cut in its own bed; but if it is of soil or sand the bed and the walls with the vaulting are to be constructed in the tunnel through which the water is to be brought.
final_alignments\Vitruvius_Architecture_Book_8.json