Deinde cellae paries conlocetur cum recessu eius a stylobata circa partem latitudinis quintam, medioque valvarum locus ad aditus relinquatur; eaque cella tantam habeat diametrum praeter parietes et circumitionem, quantam altitudinem columna.
then the wall of the cella is to be built set back from the edge of the stylobate about 1/5 of the width. In the middle is to be left an opening with folding-doors for the approach. The cella within the walls and colonnade, is to have a diameter equal to the height of the column.
final_alignments\Vitruvius_Architecture_Book_4.json