Note 18 — Chapter IV · PART I. THE AQUEDUCTS.
Reading edition
This is on the line of the wall of Servius Tullius. It appears that Trajan made a reservoir here over the old one. The specus of the Appia passes through the present gardener’s house lengthwise, from east to west. This specus was found again in another excavation to the west of it, by the side of the present road.