Site the baths where it is warmest, turned away from the north and north-east, and light the hot and tepid rooms from the south-west, since people bathe from midday to evening.
Vitruvius goes on to describe the hypocaust (a floor raised on brick piers, sloping towards the furnace so that heat runs under it) and to ask that men’s and women’s hot baths share one furnace.
Raise the central nave above the lean-to roofs of the aisles and pierce the upper walls with a row of windows, the clerestory, so that the middle of a wide hall is lit from high on both sides.
nave height ≈ 1½–2 × nave width; one window over each bay of the arcade
Edge the beds before the portico with box, clip box into figures of animals set facing one another, and in the garden beyond cut it into many shapes, even into the letters of the owner’s name.
Lay out a city’s streets so that they do not line up with the directions of the principal winds, which otherwise rush down them cold, violent and unhealthy.
For a hall of assembly use the “D” or tribune plan, a half-circle closed by a straight side: it gives ample room to the audience, a central place to the speaker and scope for display in the architecture.
Make the sweating room of a bath circular, as high to the springing of its dome as it is wide, with an opening at the crown closed by a bronze disc that can be raised and lowered on chains to regulate the heat.
height to springing = width; oculus with a movable bronze shield
Lay the channel of an aqueduct with a steady fall of not less than a quarter of an inch in every hundred feet, cover it with a vault against the sun, and carry it through hills in tunnels and across valleys on arches.
minimum fall ≈ 1 : 4,800 (Morgan’s reading); Nîmes aqueduct: ≈ 12.6 m in ≈ 50 km ≈ 1 : 4,000
Cite this page Chris Paton, “Baths in the warmest place”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/vitruvius-baths-site. Text, drawings and models licensed under CC BY-NC 4.0.