Huius antemeridiana hora circiter hora quinta sumenda est extrema gnomonis umbra et puncto signanda, deinde circino diducto ad punctum, quod est gnomonis umbrae longitudinis signum, ex eoque a centro circumagenda linea rotundationis.
Before midday, at about the fifth hour, the end of the shadow of the indicator is to be taken and marked with a point. Then a radius being taken from the indicator to the point which marks the length of the shadow, with that, from the indicator as centre, a circumference is to be drawn.
final_alignments\Vitruvius_Architecture_Book_1.json