DESK ARRANGEMENTS. 23 



In some of the rooms, especially those devoted to mineral analysis, 

 sugar and foods, etc., one end of this window desk is left free 

 without incumbrance of any kind, for the purpose of permanently 

 placing burettes for making titrations. The central large labora- 

 tory desk is placed in most of the chemical rooms just as it is in 

 the biological laboratory, with this difference, that it has two 

 central troughs connected with the large sink, is equipped with 

 a reagent shelf in the middle, and is provided with the usual con- 

 nections throughout its length for compressed air, water, and 

 vacuum. 1 



The hoods in the chemical laboratory are of necessity much 

 larger than they are in those portions of the building devoted to 

 other work, some of them being 9 and others 12 and even 15 feet 

 in length. The size of the flue for each hood is calculated so as to 

 equalize in all the time necessary to effect a change of air ; through- 

 out the building they are provided with rising sash and glass fronts 

 and sides. 2 



All the hoods in the chemical wing have not only gas, water, and 

 vacuum but also steam and steam-exhaust pipes, so that evapo- 

 rations may be continuously carried on without vitiating the 

 air of the rooms. The wall tables opposite the hoods are equipped 

 much in the same manner as are those in the biological wing, 

 but a number of them, in rooms where this is necessary, have pipes 

 for air pressure and steam as well. Storage-battery connections 

 are found on the desks of the rooms devoted to mineral analysis, 

 physics, and weights and measures, spectrum analysis, and in the 

 private laboratory of the Superintendent. It is intended to utilize 

 electrolytic methods of analysis to the fullest extent when the 

 building is in complete operation, and as in this class of work it is 

 necessary not infrequently, owing to acid fumes, to have the appara- 

 tus set up outside of the general laboratory air, these connections 

 were also placed in the hoods. 



Certain rooms devoted to specific purposes vary somewhat from 

 the general type. On the ground floor entering from the east the 

 first one to the right is devoted to physics and physical chemistry. 

 It is provided with a large central pier with cement posts above 



1 PL XIII is a photograph of the central desk in the chemical laboratory 

 and PI. XIV of the same class in the biological laboratory. 



2 PI. XV is a photograph of one of the larger hoods in the chemical 

 laboratory. 



