Jan., 1908. Annual Report of the Director. 137 



Halls 63 and 64, have also been installed as received. A total of 

 5,469 specimens is now on exhibition in this collection. The remainder 

 of the collection, classified and arranged for study purposes, occu- 

 pies drawers below the corresponding exhibition cases. The work 

 of providing additional permanent cases for the collections has 

 been continued by furnishing such cases for the systematic rock, 

 marble, and building stone collections. These occupy Halls 66 and 

 67. The specimens and old cases were entirely removed from 

 these halls, and the walls of Hall 66 renovated and calcimined. 

 Part of the cases removed were transferred to another depart- 

 ment, while others were, with some alterations, placed in the 

 departmental library. The new cases provided for the lithological 

 collection are, in general, of the pattern employed for the systematic 

 collection of minerals. The wall cases are, however, one foot instead 

 of two feet deep, and the floor cases are fitted with glass at the ends 

 as well as at the sides. The lights of the wall cases are 68 by 70 inches 

 in dimension, and swing outward by means of hinges at the top. 

 The specimens are installed on four series of six-inch shelves, sup- 

 ported by L-shaped brackets screwed to narrow iron strips bolted 

 to the backs of the cases. The lights in the floor cases are 34 by 56 

 inches in dimension, and swing outward from the top. The speci- 

 mens are installed on individual wooden blocks screwed to pyramidal 

 screens which occupy the case interiors. The blocks are distributed 

 so as to avoid a monotonous appearance, and allow for the exhibition 

 of about one hundred specimens in each case. Drawers in the bases 

 of the cases provide space for study collections. Sixteen cases in 

 all have been provided for this hall, eight of which are floor cases, 

 and eight wall cases. For the marble collection, the type of cases 

 employed is like that already in use in Skiff Hall. In place of shelves, 

 however, screens are provided to which the slabs of marble are fas- 

 tened. The slabs are thus brought in uniform position and close to 

 the eye, while the background enhances the appearance of the whole. 

 Moreover, as in the meteorite cases, the sashes are secured by locks, and 

 felted tongues and grooves, along all unjoined surfaces prevent 

 the entrance of dust. For the installation of objects other than 

 slabs, such as cubes, spheres, and other irregularly shaped specimens, 

 flat cases have been provided. These cases are 44 inches high and 4 by 6 

 feet in area. The height of the case portion proper is 1 2 inches. This 

 portion is framed together, with the end lights removable. It rests 

 upon four stout legs, tapering to the floor, all being capable of 



