110 UNITED STATES NATIONAL MUSEUM 



ground floor, while the height of the uprights of the stacks above the 

 slate floor is 9 feet 1^ inches. Around the stacks the mezzanine floor 

 is edged with a curb of 2 by 2-inch angle iron at a distance of 2 inches 

 from the front of the bottom shelf in each stack, this interspace 

 aiding in the circulation of air between the two stories. 



The provisions for reaching the mezzanine floor consist of an 

 elevator in each of the enclosures and a flight of stairs in each except 

 that occupied by the division of mollusks, where the space is in- 

 sufficient to permit of the introduction of both means of communica- 

 tion. All are located against the outer wall, adjoining door openings. 

 The elevators are operated by hand, and are of simple steel frame 

 construction with the platform measuring 4 feet 4| inches by 2 feet 

 5^ inches. They are thus of a size to accommodate the 36 by 18-inch 

 trucks which are used for carrying the bottles, jars and tanks of 

 alcoholic specimens between the laboratories and the storage rooms, 

 and through the passageways between the stacks. The stairs are 

 entirely of steel and of plain, openwork construction, but, on account 

 of the restricted space available for the purpose, it has been necessary 

 to build them steep and ladderlike. Each of the three larger rooms 

 also contains a large soapstone sink with running water. 



The shelves are finished in baked enamel of an olive green color, 

 while all the other steel work in the compartment, including that of 

 the stacks, the mezzanine floor, the stairs and elevators, are painted 

 the same color. The under side of the slate in the mezzanine floor is 

 painted white, and the upper surface is oiled to keep the dust laid. 



The capacity of the storage compartment cannot be computed 

 with any degree of definiteness on account of the varying character 

 and sizes of the containers in which the alcoholic specimens are 

 preserved. The larger and heavier receptacles, such as tanks, are 

 kept on the floor at the base of the stacks, but jars of considerable 

 size may be stored on the shelves at any convenient height. It has 

 been stated that the shelves are of three widths. The 12-inch 

 shelves are used only in the double stacks which contain no other 

 widths. The 16-inch shelves are peculiar to the stacks along the 

 two sides of the longitudinal macite partition, and the 18-inch shelves 

 to those at the ends of the rooms and along the outer walls. With 

 an allowance of 12 inches for the average height of the interspaces 

 between shelves, seven shelves may be accommodated below the 

 mezzanine floor and eight above, a total of fifteen, not counting 

 the ground floor space below the lower shelf. On this basis the 

 stack capacity is equivalent to 27,180 lineal feet of 12-inch shelving, 

 2,250 feet of 16-inch shelving, and 2,520 feet of 18-inch shelving, 

 or a total of 31,950 lineal and 33,960 square feet of shelf surface. 

 The present installation, which is somewhat less,, is as follows: 

 Of 12-inch shelving, 22,920J lineal feet; of 16-inch shelving, 1,959 



