90 UNITED STATES NATIONAL MUSEUM 



The south approach to the building is still without fixtures, but 

 at the north approach two 10-foot cast-iron street lamj) posts, each 

 carrying a 14-inch white glass globe with a 250-watt tungsten lamp, 

 have been installed, one on each side of the entrance. 



The desk lamps employed in the laboratories and offices are mostly 

 of the flexible goose neck pattern, although some other simple kinds 

 are used. The desk fans are connected with the same receptacle 

 outlets as these lamps. 



Patrol systeon. — For the convenience of the watchmen in making 

 their rounds, a. few widely separated ceiling lights, composing the 

 so-called patrol system, are kept burning all night. Their control 

 is by distinct switches, one on each of the ceiling distribution panels, 

 connecting with four panels back of the main distribution switch- 

 board in the ground story, and from these in turn with the patrol 

 panel in the generator switchboard from which the patrol lights 

 may be regulated irrespective of the general system. 



Motors, — The total number of motors in the electrical equipment 

 of the Museum is 65, of which 51 are in the new building and 14 in 

 the other buildings. Sixteen of these, mainly connected with the 

 operation of the elevators, and of the ventilating and engine room 

 fans, are of 12 to 25 horse power each. The remainder range in 

 size from ^ to T-|- horse power and are used for a variety of purposes. 



Connections with other buildings. — The electrical connections with 

 the older Museum and Smithsonian buildings are made from the 

 generator switchboard through a 9-way terra cotta conduit in the 

 underground tunnel already described. The present installation 

 consists of two separate lines of three cables each, two of the cables 

 in each line being of 500,000 circular mils and one of 250,000 circular 

 mils. From the southern end of the tunnel they are carried eastward 

 along the ceiling of the basement corridor in the Smithsonian build- 

 ing. One line stops at a switchboard in the eastern end of this 

 building, while the other continues to the main switchboard in the 

 southwest pavilion of the older Museum building. 



VENTILATION 



General system. — The ventilation of the building in general and of 

 certain parts of it in particular has been provided for through 

 mechanical agencies. In view, however, of the large open spaces 

 characteristic of the greater part of the building, it was not con- 

 sidered necessary to extend the direct operation of the general sys- 

 tem to all the stories, and it has been worked out most completely for 

 the third story. The machinery is located in the attic spaces of the 

 three wings and consists of powerful fans which operate to with- 

 draw the air from the several stories, either directly through flues 



