A Q UED UCTS. 



31 



filtering-places, those of the Claudia and Anio Novus were under- 

 ground, and now appear simply as mounds. The others were above- 

 ground, but covered over. From this point two magnificent arcades, 

 the Marciau and the Claudian, extended to the city the one carrying 

 three aqueducts, the other two. They were not more than 100 yards 

 apart, and the Marcian was 30 feet high, the Claudian 50. The filter- 

 ing-places were of peculiar construction and admirable design. They 

 consisted of four chambers, two on a level with the conduit, and two 

 directly below (Fig. 2). The water flowing into the first descended 



Fig. 2. Section op the Piscina op the Anio Novus, at the Entrance into Eome in a Tower 

 of the Wall of Aureliau and of the Gardens of the Sessorifin Palace. 



through an opening in the floor to the second, whence it flowed on 

 through a perforated wall or grating to the third, ascending from that 

 through an opening in the roof to the fourth, where it found its origi- 

 nal level and reentered the conduit. A stairway descending to an 

 opening afforded access into the chambers beneath, and by the assist- 

 ance of sluice-gates the water could be turned directly from the 

 first chamber into the fourth, so that the mud could be cleaned out 

 of the chambers below. It is remarkable that this ingjenious device 

 for filtering has not occurred to modern aqueduct-builders, for its 

 simplicity and utility are conspicuous. 



The details of distribution are interesting, but we have not space 

 to go far into them. There were 247 main reservoirs in the city, from 

 which the water was distributed to 19 barracks for the use of the 

 army, 95 public establishments, 39 theatres and places of amusement, 

 and 591 open reservoirs for the public. That was in the time of 



