CONTEOL OF INCUBATIISTG TEMPEEATURES IX LABORATORIES. 3 



at the walls. The floor was sloped to the center to facilitate cleaning 

 and disinfecting. 



Walls (Old ceiling. — Expanded-metal walls and ceiling were con- 

 structed, as shown in figure 2. These consisted of 1-inch channel 

 studs, tied at the floor and ceiling and thoroughly crosstied. The 

 studs were covered with Xo. 21 gauge high-rib expanded-metal laths 

 which were used instead of channels in order to give greater strength. 



Fi<3. 1. — Chart showing drop in room temperature for one week, vAth heat supply entirely 



shut oEf. 



Directly on the expanded niotal a i-inch course of cement mortar was 

 applied, mixed in the proportion of 1 part of Portland cement to 2 

 parts clean, sharp sand. 



"While the mortar was green a course of 2-inch cork board was 

 erected on it and the joints were slushed with hot asphalt. Against 

 the exposed surface of the cork board a Portland-cement plaster 

 finish about one-half inch in thickness was applied in two coats. 

 The first coat, about one-fourth inch in thickness, was mixed in the 



