ARTICLE I.
Of Aqueducts.
N Order to the bringing of Waters to Towns and Cities, the Level must be exactly taken; to the end, it may be known whether the Waters can be brought thither or no. The Ancients to this end made Lib. 8
Chap. 6. use of an Instrument called Corobates, which was directed by a Lead, and by Water, when the Wind hindered them from making use of the Lead.
They brought their Water three several ways; viz. by Aqueducts, by Pipes of Lead, and Pipes baked in a Potter’s Furnace. They allowed for the Channels or Sewers of the Aqueducts, for every 100 Foot, half a Foot of Declination or Sloping; and if any Hills were in their way, they dug through them, making Vents to give Air at convenient Distances.
The Pipes of Lead were at least 9 Foot long; they made them of bended Sheets or Plates, and of different thicknesses, according to the Proportion of the greatness of the Pipes; these Pipes had likewise their necessary Declination or Sloping, and if any Valley was in the way, they made it equal to the Level with a Wall; they likewise made many Vents, to give the Water Air, and to know where to mend the Pipes.
The Pipes of Potter’s-Work, were two Inches thick; they were joyned together with Mortar mixed with Oil, and when they had Conde or Joynt to make, they made use of a red Free Stone which they pierced through, to receive the two Ends of the Pipes.