STUDIES ON MUSEUMS AND KINDRED INSTITUTIONS. 487 



double faced, so tliat a depth of Tf inches is provided for the books; 

 eight or nine rows stand abreast in a room separated by a middle pas- 

 sage into two groups each U feet long. Each such stack 13 teet 9 

 inches lono-, is divided for the purpose of fastening tlie shelf supports, 

 into five sections, each 2 feet 9 inches long. The passageway is 4 feet 

 3 inches wide, and the side passages about 40 inches wide. The 

 stacks in the public liljrary are of a light blue color, covered with a 

 lacquer which feels like velvet, so that the books can not be injured; 

 all anoles in addition are rounded. The shelves, of iron, are easily 

 adjusted by means of grooves 1 inch apart; practical holders, adjusta- 



U.— Chk-ago rublie Library. Series of book stacks. 



ble above, prevent the books from falling down on shelves not entirely 

 full (tio-. 65). The space between the shelves is usually about 9 inches. 

 The stacks arc entirely open, so that air can circulate freely, which is 

 considered important for the ventilation of the books. Whether expe- 

 rience has shown that books on open shelves are preserved better than 

 those in closed cases is unknown to me. Around the bottom of the 

 stacks (see tig. 66) and along the walls run ventilating slits. Pig. bb 

 gives a view in a middle passage in the periodical room lu the third 

 • story. Fig. 67 shows an arrangement with which, by means ot 

 extensible grills, single sections can be cut otf. Fig. 6S shows a 

 room for folios (the picture represents the room for bound newspa- 



