# Illustrated Companion to the Latin Dictionary/Atrium

This article incorporates text from a publication now in the public domain: Rich, Anthony (1849). The illustrated companion to the Latin dictionary, and Greek lexicon. p. vi. OCLC 894670115. https://archive.org/details/illustratedcompa00rich.
A'TRIUM. A large apartment, constituting the first of the two principal parts into which the ground-plan of a Roman house was divided. It was approached directly from the entrance hall or passage (prothyrum), and in early times served the family as the common place of reunion, or public room of the house, in which the women worked at their looms, the family statues and ancestral images were displayed, the household gods and their altar, as well as the kitchen hearth (focus), were situated. Its relative position with regard to the rest of the mansion is shown in the two first ground-plans which illustrate the word DOMUS, on which it is marked B.
As regards the internal structure, it consisted of a rectangular apartment, the sides of which were covered over with a roof, having in most cases an aperture in the centre (compluvium), and a corresponding basin in the floor (impluvium), to receive the rain water which flowed in through the opening (see the next wood-cut). The roof itself was frequently supported upon columns, which thus formed a colonnade or open cloister round its sides (see wood-cut No. 3.). But as the roof was constructed and supported in several different ways, each of which gave a different character to the interior, these varieties were classed under the following separate names, to distinguish the different styles adopted in their construction: —
1. Atrium Tuscanicum. The Tuscan atrium; the simplest and probably most ancient of all, which was adopted at Rome from the Etruscans, and could only be employed for an apartment of small dimensions. Its peculiarity consisted in not having any columns to support the roof, which ran round its sides, and was carried upon two beams placed lengthwise from wall to wall, into which two shorter ones were mortized at equal distances from the wall, so as to form a square opening in the centre between them (Vitruv. i. 6. 2.), as seen in the engraving above (Atrium/1.1), which presents a restoration of the Etruscan atrium to the house of Sallust at Pompeii.
2. Atrium Tetrastylum. The tetrastyle atrium, so termed because its roof was supported upon four columns, one at each angle of the impluvium. The illustration (Atrium/2.1) affords a specimen of this style from a house at Pompeii, excavated by General Championet; from the preceding example, it is easy to imagine a restoration of the roof, which, when it rests upon the four columns, will form a covered gallery round the sides of the room, with an opening in the centre between them, similar to the one there shown, but with the decoration of a column at each of its corners.
3. Atrium Corinthium. The Corinthian atrium, which was of the same description as the last, but of greater size and magnificence, inasmuch as the columns which supported its roof were more numerous, and placed at a distance back from the impluvium. The central part was also open to the sky, as in the example (Atrium/3.1), from a Corinthian atrium at Pompeii, restored after the pattern of a house which was discovered with its upper story entire at Herculaneum, and an elevation of which is introduced in the article DOMUS. In this style of construction, one end of every beam which bore the roof, and formed a ceiling to the colonnade round the room, rested upon the head of each column, the other one upon the side wall, instead of being placed parallel to it, as in the Tuscan and tetrastyle; they are thus arranged at right angles to the walls, or in other words, recede from them, which is what is meant by the expression of Vitruvius, à parietibus recedunt.
4. Atrium displuviatum. An atrium, the roof of which was formed in a shelving direction, with the slant turned outwards from the compluvium, instead of towards it, and which, therefore, shot off the water from the house into gutters on the outside, instead of conducting it into the impluvium, as in the three preceding instances. Such a plan of construction is clearly shown in the diagram annexed (Atrium/4.1), from the marble plan of Rome, where the opening in the centre and the outward shelve of the roof is very cleverly expressed.
5. Atrium testudinatum. The testudinated or covered atrium, which had no compluvium, the whole apartment being entirely covered over by a roof of the kind termed testudo (Vitruv. v. 1.), which is also cleverly expressed by the artist who executed the marble plan of Rome, from which the illustration (Atrium/5.1) is selected. It is probable that an atrium of this description consisted of two stories, and that it received its light from windows in the upper one. Compare also CAVAEDIUM.
* Atrium/1.1
* Atrium/2.1
* Atrium/3.1
* Atrium/4.1
* Atrium/5.1