6.  The Thermae were composed of bathing-halls furnished with basins.  The heat was provided by a furnace placed in an underground chamber.  The Thermae in a Roman city were what the gymnasium was in a Greek city—­a rendezvous for the idle.  Much more than the gymnasium it was a labyrinth of halls of every sort:  there were a cool hall, warm apartments, a robing-room, a hall where the body was anointed with oil, parlors, halls for exercise, gardens, and the whole surrounded by an enormous wall.  Thus the Thermae of Caracalla covered an immense area.

  7.  The Bridge and the Aqueduct were supported by a range of
  arches thrown over a river or over a valley.  Examples are the
  bridge of Alcantara and the Pont du Gard.

8.  The House of a rich Roman was a work of art.  Unlike our modern houses, the ancient house had no facade; the house was turned entirely toward the interior; on the outside it showed only bare walls.

The rooms were small, ill furnished, and dark; they were lighted only through the atrium.  In the centre was the great hall of honor (the atrium) where the statues of the ancestors were erected and where visitors were received.  It was illuminated by an opening in the roof.

Behind the atrium was the peristyle, a garden surrounded by colonnades, in which were the dining halls, richly ornamented and provided with couches, for among the rich Romans, as among the Asiatic Greeks, guests reclined on couches at the banquets.  The pavement was often made of mosaic.

=Character of the Roman Architecture.=—­The Romans,[162] unlike the Greeks, did not always build in marble.  Ordinarily they used the stone that they found in the country, binding this together with an indestructible mortar which has resisted even dampness for eighteen hundred years.  Their monuments have not the wonderful grace of the Greek monuments, but they are large, strong, and solid—­like the Roman power.  The soil of the empire is still covered with their debris.  We are astonished to find monuments almost intact as remote as the deserts of Africa.  When it was planned to furnish a water-system for the city of Tunis, all that had to be done was to repair a Roman aqueduct.

=Rome and Its Monuments.=—­Rome at the time of the emperors was a city of 2,000,000 inhabitants.[163] This population was herded in houses of five and six stories, poorly built and crowded together.  The populous quarters were a labyrinth of tortuous paths, steep, and ill paved.  Juvenal who frequented them leaves us a picture of them which has little attractiveness.  At Pompeii, a city of luxury, it may be seen how narrow were the streets of a Roman city.  In the midst of hovels monuments by the hundred would be erected.  The emperor Augustus boasted of having restored more than eighty temples.  “I found a city of bricks,” said he; “I leave a city of marble.”  His successors