Quae sic erunt experienda, uti procumbatur in dentes, antequam sol exortus fuerit, in locis, quibus erit quaerendum, et in terra mento conlocato et fulto prospiciantur eae regiones; sic enim non errabit excelsius quam oporteat visus, cum erit inmotum mentum, sed libratam altitudinem in regionibus certa finitione designabit.
The method of trial is to fall on ones face before sunrise in the place where the search is to take place, and placing and supporting ones chin on the ground, to look round the neighbourhood. For when the chin is fixed, the sight will not wander higher than it ought, but will mark the same level throughout the landscape, with a definitely limited height.
final_alignments\Vitruvius_Architecture_Book_8.json