68 UNITED STATES NATIONAL MUSEUM 



the course of cracks occurring from any cause. The customary dull 

 surface of the terrazzo floors has been brightened and the colors of 

 the marble have been brought out by the application of a mixture of 

 wax, raw linseed oil, turpentine and drier, followed after the lapse of 

 a few days, by scrubbing with a weak solution of iye in warm water. 

 The color effect so produced varies from a brownish to a grayish 

 yellow. 



Wood floors'. — The lumber used for the wood floors is of uniform 

 first quality Georgia pine, close edge grain, all heart wood, and 

 specified to contain not exceeding 10 per cent of sound sap in any 

 piece. The boards are 2^ inches wide, tongued and grooved, and 

 dressed to a thickness of l^V inches. The sleepers are of the same 

 kind and grade of lumber. They measure 2 by 3 inches, and rest 

 upon a concrete base. In the third story a shallow space or air 

 chamber, with cement fire stops, underlies the flooring, but in the 

 ground story the entire space between the sleepers is filled with 

 cinder concrete. As all partitions except a few built since the com- 

 pletion of the building reach to the concrete base, the floors are 

 individual to each room, connecting only at door openings. 



Cement -floors. — The cement floors consist of a top coating 1 inch 

 thick, composed of Portland cement and clean sharp sand, followed 

 by a binder, which in the ground story is 3 inches thick and is laid 

 upon a concrete base, but in the other stories is 4 inches thick and 

 rests directly on the floor construction. The surface, except in con- 

 fined spaces, is cut by grooves into squares measuring from about 

 3 to 3^ feet across. 



WALL BASES 



Nearly all walls and piers in the several stories below the attic, 

 with the exception of most of the east wing and the enclosed middle 

 part of the west wing in the ground story, are finished with bases 

 which have already been described for some parts of the building. 

 Pink Tennessee marble, 12 inches high, occurs in connection with 

 all the terrazzo floors, the marble floors outside of the south pavilion 

 and toilet rooms, and the wood floors in the middle Aving and ranges 

 of the ground story. In the south pavilion and rotunda the bases 

 are also of Tennessee marble, the roseal variety being used on the 

 main floor and the pink variety in the galleries, but their height 

 varies in the different stories. In the toilet rooms they are of white 

 marble. Cement has been employed in connection with the cement 

 floors, and also with the wood floors throughout the third story and 

 in the ground story of the west wing. The bases of this material 

 measure generally 12 inches high in the ground story and 8^ inches 

 high in the third story. In a few small ojfice rooms wood has been 

 used. 



