PORTICUS
the Roman adaptation of the Greek a-ro, varying more or less in detail, but consisting in general of a covered colonnade formed by a wall and one or more parallel rows of columns, or less frequently by columns alone. There were two prevailing types, one enclosing a rectangular area, either open and laid out like a garden, or occupied by a temple, and the second a long gallery bordering on a street. In either case the porticus might be an independent structure, or attached to adjacent buildings. In the gardens of the rich Romans even the driveways seem to have been under such colonnades. The earliest porticus known to us were built in 193 B.C. by two members of the gens Aemilia, but the period of rapid development in numbers and use began in the last century of the republic and continued in the Augustan era (Stuart Jones, Companion 108-110). The earlier porticus were devoted mainly to business purposes, but during the empire they were intended primarily to provide places for walking and lounging that should be sheltered from sun and wind. For this reason the intercolumnar spaces were sometimes filled with glass or hedges of box. Within the porticus or the apartments connected with them, were collections of statuary, paintings, and works of art, as well as shops and bazaars. A porticus took its name from its builder, its purpose, the structure to which it was attached or of which it formed a part, or sometimes from some famous statue or painting preserved within it (e.g. PORTICUS ARGONAUTARUM).The campus Martius was particularly well adapted to the development of the porticus, and by the second century there were upwards of twelve in Region IX, some of them of great size, and it was possible to walk from the forum of Trajan to the pons Aelius under a continuous shelter (Vitr. i. 3. I ; v. 9. 1-5; Ann. d. Inst. 1883, 5-22; DS iv. 586; LR 447; Lanciani, Anc. Rome, 94).