40 CHEMICAL DISCOVERY AND INVENTION 



the largest amount being for doors and window frames. Some 

 rooms also contain a chain rail and a picture rail. 



Abundant hood space 1 is provided in all parts of the building. 

 The hood construction used throughout the building consists 

 of the following : the top is a single frame of plate glass with 

 wire reinforcement, so set as to avoid as far as possible the 

 gathering of dust ; the doors are counterpoised, the weights 

 being attached by means of a creasoted hemp rope. The pulleys 

 and axles are made of wood. Each hood is connected with a 

 flue which runs to the top of the building independently of 

 other hoods. Ventilation is by forced draft. In the larger 

 laboratories the air is brought in at the corners of the room, 

 and distributed at various openings along the ceiling. The foul 

 air is forced out through the hood flues. In this way there is 

 an even distribution of the fresh air in all parts of the room 

 and the air is changed six times per hour. In the laboratories 

 for elementary chemistry there are upon the student desks 

 special ventilation conduits which are connected with exhaust 

 fans capable of changing the air in these laboratories eleven 

 times per hour. The toilet rooms are provided with special 

 exhaust fans giving very thorough ventilation. 



Alberene stone is used for window-sills, shelves, and table- 

 tops. All tables are supplied with gas, water, waste, and suction ; 

 some also have air blast, high-pressure steam, distilled water, 

 and hydrogen sulphide. The building is completely wired with 

 five electric systems : 10, 110, and 220 volt direct current, and 

 110 and 220 volt alternate current. Many laboratories are also 

 connected with the storage battery system. In the attic a large 

 water distillation apparatus is placed as well as a hydrogen 

 sulphide generator. The hydrogen sulphide is stored in a 500- 

 gallon gas tank, which permits the supply of the gas to various 

 parts of the building under constant pressure. 



Besides the main lecture room, which seats 390, there is one 

 smaller lecture room ; 7 recitation rooms and 4 seminar rooms 

 are also provided. 



Fire-proof vaults and an elevator are available from all floors. 



The general plan of space distribution is to have most of the 



offices, the library, and the research laboratories in the new 



part, with the routine laboratories in the old ; the office of the 



director and the general executive offices of the department 



? This is understood to refer to chambers for carrying off fumes. 



