Note 64 — XXI. An Account of the Temple of Serapis at Pozzuoli in the Kingdom of Naples: In a Letter to John Ward, LL.D. and R.S. Vice-Præs. by the Rev. John Nixon, M.A. F.R.S.
Reading edition
Vitruvius Lib. iii. cap. 3. Gradus in fronte ita constituendi sunt, uti sint semper impares: namque cum dextro pede primus gradus ascendatur, item in templo primus erit ponendus.