\paperw4995 \margr0\margl0 \plain \fs20 \f1 \fs22 Their number grew throughout the Empire; it is thought that in Rome, whose population reached a million and a half at
its peak, there were about 900 public baths and eleven large thermae in the fourth century. The thermal complexes were some of the greatest masterpieces of Roman architecture and engineering: the rooms used for different purposes were skillfully arranged
; the magnificent \b \cf1 \ATXht22 vaulted\b0 \cf0 \ATXht0 roofs were daring and massive; the sophisticated heating systems were works of high technical skill; extreme care was taken over the architectural and decorative details.\par