NATUBAL HISTORY BUILDING 89 



designed for a 100- watt tungsten lamp. The lamps used have the 

 bowl frosted. In the third story the ceiling fixtures are made of 

 a short piece of f-inch brass tubing with a satin finish holophane 

 shade. In the rooms 100-watt lamps are employed and in the cor- 

 ridors 60-watt lamps. A few of the rooms in the ground story have 

 the same style of fixture, but with a longer stem ; while for the east 

 wing, containing the power plant, special fixtures have been made 

 of pipe and fittings to suit the different requirements. The north 

 entrance vestibule is lighted by two 60-watt Meridian tungsten 

 lamps with frosted bowls that screw into a special fixture fitting 

 close against the ceiling. The ceiling lights in the rooms are con- 

 trolled by wall switches, one inside of each door, and in the corridors 

 by switches of the same kind located in gangs at or near the end 

 of each corridor. The control of the ceiling lights in the first and 

 second stories is directly from the distribution panels. 



The east and west skylighted halls in the first story obtain their 

 general illumination from above the ceiling lights through the me- 

 dium of special Frink slrylight mirror reflectors carrying 40-watt 

 tungsten lamps. There are sixteen lines of these reflectors over each 

 ceiling light, being attached one on each side of the lower horizontal 

 member of each of the eight roof trusses spanning the light well. 

 Each line is 30 feet long, and is supplied with 32 lamps placed 

 horizontally and connected alternately in two circuits. The 32 cir- 

 cuits thus constituted in each light well are controlled by as many 

 switches contained in four panels on the walls at the pavilion end 

 of the space. 



The lighting of the picture gallery in the middle hall of the first 

 story is also accomplished by means of Frink reflectors, consisting 

 of long tin holders containing mirrors so placed as to reflect the 

 light against the screens, from which the fixtures are distant about 

 5 feet. The lamps are 25-watt tungsten, with a few of 60-watt, 

 spaced 1 foot apart. The aggregate length of the reflectors in the 

 several rooms is about Y50 feet. 



The plans for the illumination of the rotunda have not yet been 

 fully carried out, and the only fixtures so far permanently installed 

 consist of ceiling lights in the corridor and gallery back of the piers 

 and screens in the first and second stories. These are in the form of 

 pendent alabaster glass bowls, 15^ inches in diameter, attached by 

 means of three small chains to a larger one, the chains being of brass 

 finished in French lacquer gilt. The bowls, which are slightly tinted 

 to produce a somewhat subdued light, contain three outlets fitted 

 with 60-watt clear tungsten lamps resting at a slight angle to the 

 horizontal. Thin celluloid sheet covers prevent dust from entering 

 the bowls. 



