Research Buildings 191 



The building has six working levels (Figures 3 to 8) : sub-basement, devoted to heat- 

 ing and gas-making room and to constant-temperature rooms; basement, devoted to in- 

 strument shops, several testing-rooins, storage-battery room, motor-generator room, and 

 clock-room; first floor, devoted principally to laboratory rooms; second floor, devoted to 

 Director's quarters, computing-rooms, library, and archives; a spacious and well-lighted 

 attic for special laboratory work and storage purposes; and an observation deck. 



To overcome the transmission of vibration to the walls on which delicate instruments 

 were to be mounted, the floors for all rooms in which it was expected that machinery of 

 any kind would be placed have been built of concrete slabs 12 inches thick laid upon a 

 cushion of sand 6 inches thick, and separated from the walls by 6 inches of sand on all sides. 

 As it was not desirable to cut up the large instrument shop into two rooms, the wall between 

 laboratory rooms Nos. 211 and 212 is carried by means of a heavily-reinforced concrete 

 girder. To afford greater freedom from vibration the walls marked A on the plan of the 

 first floor have been made entirely free of the reinforced-concrete floors. These walls also 

 are discontinued a short distance below the ceiling of the laboratories and bear no loads 

 from above. Preliminanj tests have indicated that even luith all of the installed machinery in 

 operation there is no vihralion transmitted through the walls to interfere with readings of sensitive 

 galvanometers. 



The corridors of the building are I2h feet high and, while not quite 7 feet wide, do not 

 give the impression of narrowness, because of the arches across the width of the halls at 

 each end and the dropping of the ceilings behind these arches. The doors leading to the 

 various rooms from the corridors are all glazed with opaque rough "moss" glass. Some 

 ornamental cornice plaster work occurs in the corridors, stair-hall, and in the Director's 

 office. For the purpose of displaying a model of the non-magnetic survey yacht Carnegie, 

 a concrete platfonii and die-block has been installed at the first floor level at the center of 

 the stair-hall and mimediately in front of the vestibule entrance. 



A symbolic compass design, 25 inches in diameter and in relief in brass, is built in the 

 marble and mosaic floor of the entrance vestibule. Its general detail is copied from an old 

 compass card. The building being oriented with its long axis true northwest-southeast, 

 the fleur-de-lis of this design is on a line at 45 with the axes of the building. The vestibule 

 is paneled in cypress, finished in accord with the heavy 2j-inch 12-paneled outside doors. 



The wood-trim for all windows and doors throughout was reduced to a minunum in 

 order to lessen possible fire risk; metal corner beads have been inserted at all plaster corners 

 of the openings. The interior doors are If inches thick, 5-paneled "Korelok" with one- 

 eighth-inch birch veneer and rubbed mahogan^y finish. The trim and window casements 

 throughout are painted in a flat brown tint. The hardware is of brass with statuary bronze 

 finish. All inside walls, except as otherwise noted, are finished in plaster. 



There are but 5 observation piers ; 2 of these are carried to the floor level of the base- 

 ment, 2 are carried through the basement to the first-story rooms, Nos. 207 and 209, and 1 

 is carried from the sub-basement to the clock-room. All of these piers are built upon broad 

 concrete footing-courses laid upon sand cushions and separated from the floors by sand on 

 all sides. The piers in the adjusting-room are an integral part of the large concrete slab 

 forming the floor of this room. The practice of building a great many piers has been prac- 

 tically discontinued in recently built laboratories, as, with solid construction, the walls 

 themselves offer equally good supports for delicate instruments, particularly so when 

 reasonable precautions are taken to prevent transmission to the walls of vibration from 

 machinery in operation. There is also thus avoided the difficulty, often encountered where 

 very high piers must be built, of flexure, and the magnification of any vibration due to 

 height. 



The power for lighting, and for use in the shop and in the laboratory, is supplied by the 

 local electric power company, being delivered on the site at 2,300 volts, single-phase, alter- 

 nating current, and transfonned by a 25-kilovolt-ampere transformer, installed in the 



