416 



GENERAL SCIENCE 



will travel in parallel lines, returning toward the source; moreover, 

 all walls or ceilings which cause conflicting sound waves should be 

 constructed of dead or non-reflecting surfaces, and the resonance- 

 box and sound reflectors should be so placed in an auditorium as to 

 balance evenly the quality and volume of the sound. An oval shaped 

 room seems to be the best for producing absolutely perfect results. 

 The stage should be placed at the smaller end of the hall. Rooms 

 which havejirched ceilings are not of the best type 



PERFECT 

 100% 



VERY GOOD 

 90% 



GOOD 

 85% 



FAIR 

 70% 



PASSABLE 

 60% 



POOR 

 50% 



VERY POOR 

 45% 



BAD 

 307. 



VERY BAD 

 15% 



TOTAL 

 LOSS 



FIG. 307e. The diagrams show the shape of room best adapted for reducing 

 sound disturbances. The white dots denote the places where there is 

 a great deal of sound disturbance, which makes it difficult for people 

 sitting in that part of the room to hear. The per cent refers to the loss 

 of effective hearing qualities. X denotes the position of the speaker. 

 In what class does your auditorium belong? Your class room? 



The illustration shows some floor plans which produce varying 

 results, from perfect hearing to total loss of hearing qualities. 



The best method of supplying heated air to an auditorium is by 

 allowing the air to enter at a great many places on the floor of the 

 room. A number of openings is usually provided under each row of 

 seats so that there is a gentle and equal distribution of warm air 

 from the hot-air supply duct. 



