Jan., 1909. 



Annual Report of the Director. 



243 



mens from different localities, is also arranged to correspond with this 

 classification. In addition a small collection shows the influence of 

 various foreign matters upon the plasticity, shrinkage, color, and other 

 properties of clay. The collection of soils numbers at present one 

 hundred and fifty-five specimens. Of these a collection illustrating 

 the derivation of soils from several kinds of rocks, and a collection of 

 the essential and incidental components of soil fill two table cases. In 

 these cases is also placed a collection of plant foods as found in soils 

 and one illustrating the characteristics of the wider and well-recognized 

 groups of soils. A collection of fifty-four soils and subsoils arranged 

 according to the special classification adopted by the U. S. Department 

 of Agriculture occupies one wall case, and a collection of soils from all 

 parts of the world arranged according to the familiar groupings of 

 loams, marls, etc., occupies two table cases. The sands and cements 

 which occupy a wall case are arranged according to their industrial 

 applications, being grouped as glass sands, molding sands, etc. Trays 

 or jars are employed for the installation of the specimens in this hall, 

 according as a vertical or horizontal position is desired. A number 

 of additions were made to the collection of relief maps in Halls 76 and 

 77 and the collection rearranged. The work of framing the maps of 

 the collection was also continued and is now nearly completed, forty- 

 two large maps being at present framed. Smaller maps, which could 

 not readily be framed, were placed in floor cases, three of which were 

 provided for the purpose. Photographs of typical ancient shore lines 

 of Lake Chicago and other topographic features in the vicinity of Chi- 

 cago, made by the Curator, have been installed adjacent to the relief 

 maps of the region. Complete descriptive labels have been made for 

 a number of maps and have been attached to them in such a way as to 

 be conveniently read while examining the map. This has been accom- 

 plished by mounting them over the map in many instances and hinging 

 them so that any portion of the map covered by the label can be seen 

 by swinging the label. In Hall 78 the old cases and platforms have 

 been replaced by new cases throughout, so that all the exhibits are 

 now under glass. The large specimens formerly exhibited near the 

 walls have been brought forward to the center of the hall and promi- 

 nently displayed in three upright cases. These cases are 40 inches 

 square and 69 inches high. They have glass on all four sides and the 

 top, so that their contents are visible from all parts of the room. 

 The central case of these is occupied by large blocks of bright- 

 colored rubellite, and those on either side contain monoliths 



