213

would be colossal. I have therefore thought it expedientto state the proportions which, in all particular instances,are best calculated for convenience and beauty.

The height of the trabes, measured from the floor, shouldbe equal to the width of the tablinum, with the addition ofan eighth part: and the height of the lacunaria equal tothe same width increased by its third part.

In atria of small dimensions the entrance 1 * 3 is made twothirds the width of the tablinum; and in spacious atriait is half the width. The statues with their ornamentsshould be equal in height to the width of the alae. Theproportions of the height and width of the door-waysdepend upon the order of architecture: whether this beD oric or Ionic the proportions must be determined accordingto the principles already given for the thyromata of differentorders, in the second section.

The compluvium of the cavaedium, through which thelight is admitted, ought not to be more than a third of thewidth of the atrium nor less than a fourth; the length mustbe determined in the same manner as that of the atrium.

The peristyles should be greater in extent, measuredtransversely, than in length: the columns equal in heightto the width of the porticoes of the peristyles; the

1 The “ fauces” meant probably the entrance from the vestibule into the atrium;corresponding to the thyroreum of the Greek house ; which Vitruvius calls a passageof inconsiderable width. The word is used by Virgil in this figurative sense,

“ Angustaeque premunt fauces aditusque maligni.”

The porter’s cells were on one side of the thyroreum of a Greek house.

3 i