IMPROVEMENTS IN THEATER SANITATION. 91 



auditorium arranged very much like those at Vienna. The total 

 quantity of fresh air supplied per hour is 2,800,000 cubic feet. The 

 air enters the auditorium through gratings fixed above the floor 

 level in the risers. The foul air is removed by outlets in the ceil- 

 ings, which unite into a large vertical shaft below the cupola. An 

 exhaust fan of ten feet diameter is placed in the cupola shaft, and 

 is used for summer ventilation only. Every single box and stall 

 is ventilated separately. The cost of the entire system was about 

 one hundred and twenty-five thousand dollars; it requires a staff of 

 two engineers, six assistant engineers, and a number of stokers. 



Among well-ventilated American theaters is the Madison 

 Square Theater (now Hoyt's), in jSTew York. Here the fresh air 

 is taken down through a large vertical shaft on the side of the 

 stage. There is a seven-foot suction fan in the basement which 

 drives the air into a number of boxes with steam-heating stacks, 

 from which smaller pipes lead to openings under each row of seats. 

 The foul air escapes through openings in the ceiling and under 

 the galleries. A fresh-air supply of 1,500 cubic feet per hour, or 

 25 cubic feet per minute, per person is provided. 



The Metropolitan Opera House is ventilated on the plenum 

 system, and has an upward movement of air, the total air supply 

 being 70,000 cubic feet per hour. 



In the Academy of Music, Baltimore, the fresh air is admitted 

 mainly from the stage and the exits of foul air are in the ceiling 

 at the auditorium. 



Other theaters ventilated by the upward method are the Dres- 

 den Royal Theater, the Lessing Theater in Berlin, the Opera 

 House in Buda-Pesth, the new theater in Prague, the new Munici- 

 pal Theater at Halle, and the Criterion Theatre in London. 



The French engineer General Arthur Morin is known as the 

 principal advocate of the downward method of ventilation. This 

 was at that time a radical departure from existing methods because 

 it apparently conflicted with the well-known fact that heated air 

 naturally rises. Much the same system was advocated by Dr. 

 Tripier in a pamphlet published in 1864.* The earlier practical 

 applications of this system to several French theaters did not prove 

 as much of a success as anticipated, the failure being due probably 

 to the gas illumination, the central chandelier, and the absence of 

 mechanical means for inducing a downward movement of the air. 



In 1861 a French commission, of which General Morin was a 

 member, proposed the reversing of the currents of air by admit- 

 ting fresh air at both sides of the stage opening high up in the 

 auditorium, and also through hollow floor channels for the balconies 



* Dr. A. Tripier. Assainissement des Theatres, Yentilation, ificlairage et Chauffage. 



