Illustrated Companion to the Latin Dictionary/Cavaedium

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. 

CAVAE'DIUM or CAVUM AEDIUM. Literally, the void or hollow part of a house. To understand the real meaning of this word, it is to be observed that in early times, or for houses of small dimensions, the ancient style of building was a very simple one, and consisted in disposing all the habitable apartments round four sides of a quadrangle, which thus left a space or court-yard in the centre, without any roof, and entirely open to the sky, as shown by the annexed example (Cavaedium/1.1), from the Vatican Virgil. This hollow space received the primitive name of cavum aedium, so truly descriptive of it; and formed, with the suites of apartments all round it, the entire house. But as the Romans increased in wealth, and began to build upon a more magnificent scale, adopting the style and plans of other nations, they converted this open court into an apartment suitable to the uses of their families, by covering in the sides of it with a roof supported upon columns of one story high, and leaving only an opening in the centre (compluvium) for the admission of light and air. This practice they learnt from the Etruscans (ab Atriatibus Tuscis. Varro, L. L. v. 161.), and, therefore, when the cavum aedium was so constructed, they designated it by the name of atrium, after the people from whom they had borrowed the design. By referring to the ground-plans which illustrate the article DOMUS, it will be perceived that the atrium is in reality nothing more than the hollow part of the house, with a covered gallery or portico round its sides; and thus the two words sometimes appear to be used as convertible terms, and at others, with so much uncertainty as to bear an interpretation which would refer them to two separate and distinct members of the edifice; and, in reality, in great houses, or in country villas which covered a large space of ground, and comprised many distinct members, with their own appurtenances attached to each, we find that both a cavaedium and atrium were comprised in the general plan. This was the case in Pliny's villa (Ep. ii. 17.), in which we are to understand that the first was an open court-yard, without any roof and side galleries (whence it is expressly said to be light and cheerful, hilare); the other, a regular atrium, partially covered in, according to the Etruscan, or foreign fashion. There can be no doubt that such is the real difference between the cavaedium and atrium; but when the two words are not applied in a strictly distinctive sense, as in the passage of Pliny above cited, both the one and the other may be commonly used to designate the same member of a house, without reference to any particular position or mode of fitting up, both of them in reality being situate in the hollow, or shell of the house; and, consequently, Vitruvius, as an architect, employs the term cavaedium (vi. 5.) for the style which more strictly and accurately resembles an atrium. (See that word, and the illustrations there introduced; which will show the different ways of arranging a cavaedium, when taken in its more general meaning.)

• 
  Cavaedium/1.1