Tunc ab summo sub abaco inceptum in singulis tetrantorum actionibus dimidiatum oculi spatium minuatur, donique in eundem tetrantem qui est sub abaco, veniat.
Then, beginning from the top under the abacus, let the radius be successively diminished by half the diameter of the eye in describing the quadrants, until it comes into the quadrant which is under the abacus.
final_alignments\Vitruvius_Architecture_Book_3.json