240
THE INSULATION OF SOUND
cotta block, finished on the corridor side with plaster applied directly
to the terra cotta. The wall next the room was of gypsum block,
plastered and finished in burlap. In the air space between the two
walls, deadening sheet was hung. The walls separating the rooms
were of gypsum block and finished in hard plaster and burlap. As
shown on the diagram (Fig. 1), these walls were cellular, one
CLOfET
5ECTION THRO CORRIDOR.
PARTITION WALL
Fig. 1. Details of Construction, Institute of Musical Art,
New York, N. Y.
of these cells being entirely enclosed in gypsum block, the others
being closets opening the one to one room, the other to the other.
The closets were lined with wood sheathing which was separated
from the enclosing wall by a narrow space in which deadening sheet
was hung in double thickness with overlapping joints. In the en¬
tirely enclosed cell, deadening sheet was also hung in double thick¬
ness.