NATURAL HISTOEY BUILDING 65 



Each of the wings contains certain constructions, described else- 

 where, pertaining to the ventilating system, and a number of com- 

 partments have been enclosed by means of macite for the storage of 

 specimens under special fire-proof conditions. 



WALL, PIER AND CEILING FINISH 



All steel structural columns in the several stories, other than those 

 entirely concealed in double terra cotta walls, are so enclosed as to 

 produce piers rectangular in section whether isolated or attached, 

 the covering serving as a fire protection for the steel and adding to 

 the appearance of the halls. In the north entrance lobby the enclos- 

 ing material is marble, but elsewhere terra cotta, plastered, is ex- 

 clusively employed. x\ll piers in the first and second stories and also 

 the finished brick piers in the ground story have plaster-molded caps 

 and a base member of the same material surmounting a marble base 

 corresponding with that of the adjacent or surrounding walls. In 

 the third stoiy and attic, however, the piers are finished plain, with a 

 cement base in the third story. 



In the first story of the wings the piers measure in section 2 feet 

 by 3 feet, except the two corner ones near the outer ends of the wings 

 which are 2 feet by 5 feet. In both the first and second stories of the 

 ranges, where they are 2 feet 2 inches square over their greatest 

 dimensions, they have pilasters on all sides, 19 inches wide and pro- 

 jecting 3-|- inches. In the third story of the wings, except as noted, 

 the terra cotta coverings are built into the walls of the light wells so 

 as to form attached piers, 23 inches wide and projecting 17 inches. 

 The corner piers at the outer ends of the east and w^est wings, four 

 in all, which stand separate from the walls and slightly out of align- 

 ment with the other piers in the side rows, measure 23 inches square, 

 while the two piers in the ranges, one each in the northeast and north- 

 west corners, measure 23f by 23f inches. In the attic spaces of 

 the wings the attached and detached piers of the third story are re- 

 peated, the former measuring 22^ by 15^ inches, the latter about 20 

 by 23 inches. 



With the exceptions already and herewith noted, the surfaces of 

 walls, piers and ceilings throughout the interior of the building have 

 been treated with three-coat lime plaster having a fine lime putty 

 finish. In all ornamental work plaster of Paris has been used in the 

 proportion of 75 per cent of the mortar. All corners on plastered 

 walls, piers and pilasters not otherwise protected are strengthened 

 with heavy steel corner strips, extending 10 feet above the tops of 

 the bases. Keene's cement of the qualit}' known as " fine " or second 

 grade has been employed for the architraves, jambs and heads of 

 many openings, such as those between the wings and the ranges and 

 80120°— Bull. 80—13 5 



