328 WARMING AND VENTILATION. 



government has scarcely any control over the latter, and but little over 

 the former. Still, as the results obtained at the Lyric Theater have, in 

 the main, been somewhat satisfactory when the apparatus has been 

 properly managed, I will describe this first application, in spite of its 

 imperfections. 



The auditorium, intended to accommodate 1,700 spectators, has really 

 but 1,472 seats, distributed as follows : 



Orchestra, parquet, and lower boxes 440 



First tier , 256 



Second tier 302 



Third tier 178 



Fourth tier 296 1, 032 



1, 472 



The amount of air to be renewed for each spectator had been limited 

 to 1,060 feet an hour, which, with the above number of places, corre- 

 sponded to a total volume of 1,560,000 cubic feet an hour. The condi- 

 tions imposed upon the contractor, based on the hypothesis of 1,700 

 spectators, would requii'e a renewal of 1,800,000 cubic feet of air an hour. 



133. External-air supply. — The air-supply was taken in St. Jacques 

 Square from a circular well 12 feet in diameter, which, by a subterranean 

 passage, at first circular, 11 feet in diameter, and afterward of variable 

 form, but of the same sectional area, carried it to the subbasement of 

 the building, and spread it over the whole extent occupied by the heat- 

 ers and the air-chambers. The sectional area of the passage-way was 

 therefore but 98 square feet; and experiment (December 9, 1862*) hav- 

 ing shown that the velocity in it was as much as 6 feet a second, the 

 volume of fresh air introduced by this gallery was that day 1,090,000 

 cubic feet. It was only deemed necessary to introduce 1,060,000 cubic 

 feet, since the unavoidable admission of air through the doors, the pas- 

 sages, and the stage would easily and without inconvenience furnish the 

 balance, as has been found to be the case. It would, nevertheless, be. 

 more prudent in such cases to calculate the dimensions of the fresh-air 

 trunk to furnish the entire amount. 



134. Alteration of the adopted plans. — But a little while after the open- 

 ing or the lease of the theater to the manager, the external freshair pas- 

 sage was closed, and even the pit in St. Jacques Square covered with ivy. 

 Thus the introduction of air by these passages, as well as by the pipes 

 leading to the inteijoists of the boxes, is almost entirely jjreveuted, 

 "while the outward draught is as strong as ever. It therefore follows that, 

 to replace the air carried off, cold air enters through the halls, passages, 

 &c., which is very unpleasant for the spectators, and which the public 

 attribute to the general arrangements adopted, while they are only the 

 result of want of care and of the exercise of authority. 



* £tude8 sur la ventilation, vol. 2. 



