IMPROVEMENTS IN THEATER SANITATION. 93 



for the improvement of the ventilation of the Senate chamber and 

 the chamber of the House of Representatives in the Capitol at 

 Washington, but the system was not adopted by the Board of Engi- 

 neers appointed to inquire into the methods. 



The downward method is also used in the Hall of the Troca- 

 dero, Paris; in the old and also the new buildings for the Ger- 

 man Parliament, Berlin; in the Chamber of Deputies, Paris; and 

 others. 



Professor Fischer, a modern German authority on heating and 

 ventilation, in a discussion of the relative advantages of the two 

 methods, reaches the conclusion that both are practical and can 

 be made to work successfully. For audience halls lighted by gas- 

 lights he considers the upward method as preferable. 



In arranging for the removal of foul air it is necessary, par- 

 ticularly in the downward system, to provide separate exhaust flues 

 for the galleries and balconies. Unless this is provided for, the 

 exhaled air of the occupants of the higher tiers would mingle 

 with the descending current of pure air supplied to the occupants 

 of the main auditorium floor. 



]\Iention should also be made of a proposition originating in 

 Berlin to construct the roof of auditoriums domelike, by dividing 

 it in the middle so that it can be partly opened by means of elec- 

 tric or hydraulic machinery; such a system would permit of keep- 

 ing the ceiling open in summer time, thereby rendering the theater 

 not only airy, but also free from the danger of smoke. A system 

 based on similar principles is in actual use at the Madison Square 

 Garden, in New York, where part of the roof consists of sliding 

 skylights which in summer time can be made to open or close dur- 

 ing the performance. 



From the point of view of safety in case of fire, which usually 

 in a theater breaks out on the stage, it is without doubt best to 

 have the air currents travel in a direction from the auditorium 

 toward the stage roof. This has been successfully arranged in 

 some of the later Vienna theaters, but from the point of view of 

 good acoustics, it is better to have the air currents travel from the 

 stage toward the auditorium. Obviously, it is a somewhat diflicult 

 matter to reconcile the conflicting requirements of safety from 

 smoke and fire gases, good acoustics and perfect ventilation. 



The stage of a theater requires to be well ventilated, for often 

 it becomes filled with smoke or gases due to firing of guns, colored 

 lights, torches, representations of battles, etc. There should be in 

 the roof over the stage large outlet flues, or sliding skylights, con- 

 trolled from the stage for the removal of the smoke. These, in 

 case of an outbreak of fire on the stage, become of vital impor- 



