PLATE 8. 
Hy. 
| 
i} 
A thermostat-room, 
In the center of the building and lighted by electricity. Ventilated in the same way as the photographic dark-rooms, i- e-, by an exhaust-fan 
run by an electric motor. Three of the thermostats were made by Bausch & Lomb, the fourth (felted) is a Rohrbeck. 
