267, seq.).

In reality it may be traceable simply to the fact, that the circular shape has constantly been recognized as the most convenient and the safest form of a space destined for enclosure and custody.
That was the rationale of the round -- thesauroi-- of the Greeks as well as of the round structure of the Roman store-chamber or temple of the Penates.

It was natural, also, that the fireplace--that is, the altar of Vesta--and the fire-chamber--that is, the temple of Vesta -- should be constructed of a round form, just as was done with the cistern and the well-enclosure (-puteal-).

The round style of building in itself was Graeco-Italian as was the square form, and the former was appropriated to the store-place, the latter to the dwelling-house; but the architectural and religious development of the simple -tholos- into the round temple with pillars and columns was Latin.
38.

I.XV.Plastic Art in Italy 39.