270 REPOET OF NATIONAL MUSEUM, 1891. 



EXPLANATION OF DIAGRAM. 



1, "Wall case containing collection of elements, rock-forming minerals, color, structure, and fracture 

 series ; 2 to 10, inclusive, table cases with slope-top cases containing systematic series of rocks ; 11, table 

 case with slope-top case containingj volcanic materials ; 12, floor upright case with calcareous and silice- 

 ous deposits from hot springs, geysers, and extinct lakes; 13, lialf unit table case with model of Vesu- 

 vius ; 14, table case with slope-top case containing lavas from Ice Spring Buttes, Utah ; 15, table case with 

 special top containing collections illustrating stratification and its accompaniments; 16, door-screen 

 case with type collections, rocks of Comstock Lode and Washoo district, Nevada; 17, door-screen case 

 with collections illustrating the geology and mineralogy of the District of Columbia; 18, special base 

 with large concretions from Cannon Ball Elver, Dakota ; 19, table case with large masses of obsidian ; 

 20, half unit table case with blocks of glacial polished and striated limestone; 21, wall case containing 

 series illustrating joiuts, faults, veins, and pressure cflects; 22, wall case containing concretions; 23, 

 wall case containing coUoctions illustrating («) formation of pebbles by wave action on a beach, (6) 

 the drifting power of water, (c) effects of lightning (fulgurites), (rf) rock decomposition and the for- 

 mation of soils, (c) sand blast erosion, (/) drifting power of wind, and (g) ccmtact metamorphism ; 24, 

 25, and 26, door-screen cases with buildiiig and ornamental stones; 27, special case with large geyser 

 cone ; 28, floor tipriglit case with stalactite and stalagmites ; 29 and 30, table cases with relief maps ; 

 31," 32, and 33, door-sci-een cases with building and ornamental stones; 34 and 35, table cases with 

 building and ornamental stones showing styles of dressing; 36, 37, and 38, door screen cases with 

 building and ornamental stones; 39, 40, 41, and 42, table cases with rii)ple marks, mud cracks, foot, 

 prints, etc. ; 43 to 48 inclusive, door-screeu cases with building and ornamental stones; 49, large block 

 of glaciated limestone; 50, table case with slope-top case containing glacial exhibits; 51, relief map of 

 Grand Canyon district; 52, table case with wing frames for pictures; 53 and 54, relief maps of the 

 Uinta and "Wasatch mountains, Yellowstone Park, high plateaus of Utah, and Mount Taylor, New 

 Mexico; 55 and 56, pier cases with foreign building and ornamental stone; 57, pier cases with collec- 

 tions showing reproductive and constructive eflocts of plant and animal life, the geology of Bermuda; 

 58, pier cases with collection illustrating the origin of serpentinous rocks; 59, wall case with rocks of 

 New Hampshire; 60, wall case with historical series included type series rocks of Canada; 61 and 62, 

 columns of grindstones ; 63, table with books for reference. 



