4. But if the columns are to be Ionic, let the shaft, excluding base and capital, be divided into eight and one half parts, and let one of these be assigned to the thickness of a column. Let the base, including the plinth, be fixed at half the thickness, and let the proportions of the capital be as shown in the third book. If the column is to be Corinthian, let its shaft and base be proportioned as in the Ionic, but its capital, as has been written in the fourth book. In the stylobates, let the increase made there by means of the “scamilli impares” be taken from the description written above in the third book. Let the architraves, coronae, and all the rest be developed, in proportion to the columns, from what has been written in the foregoing books.