Et a linea, quae erit planities in linea gnomonis circino novem spatia demetiantur; et quo loco nonae partis signum fuerit, centrum constituatur, ubi erit littera a; et deducto circino ab eo centro ad lineam planitiae, ubi erit littera b, circinatio circuli describatur, quae dicitur meridiana.
and on the line where the level surface is, let nine parts be measured starting from the foot of the gnomon; where the end of the ninth part is marked, let a centre be taken and indicated by the letter a; and extending the compasses from that centre to a point in the line, to be indicated by the letter b, let the circumference of the circle be described which we call the meridian.
final_alignments\Vitruvius_Architecture_Book_9.json