40 
Pedestal 12. — Two large masses of Canon Diablo, Arizona, 
meteorites, weight 1013 and 265 pounds. 
Note the natural perforation through which the chain passes 
by which the smaller one is hung. It well illustrates the auger- 
like action of the air to which a meteorite is exposed during its 
passage to the earth. These meteorites are also remarkable as 
containing minute diamonds. 
North Wall. — Map showing distribution of meteorite falls in 
the United States. The apparent paucity of falls in the Western 
States is due to a lack of population there rather than to a lack of 
falls. 
For detailed information regarding the specimens and 
meteorites in general, the Guide and Handbook of the collection, 
a copy of which will be found in the Hall, may be consulted. 
HALLS 63 AND 64. 
SYSTEMATIC MINERALOGY. 
The systematic collection of minerals numbers about 5,000 
specimens. The arrangement of the collection is based upon that 
given in Dana’s New System of Mineralogy, and so far as possible 
the purpose has been to illustrate the different species there dis- 
cribed. A copy of this work may be found in the library. The 
order which is to be followed in a study of the collection is shown 
by the numbering of the cases. Thus, entering Hall 63 from the 
south, the visitor finds case No. i at his or her left, and the order 
then follows along the west wall through the oxides in Case 4, 
back on the western side of the center aisle, down the eastern 
side, and back along the east wall ; then passing to Hall 64, the 
order continues with the phosphates in Case 15 on the western 
side and ends with Case 17 on the eastern side. 
Complete case labels above each case indicate the groups to 
which the specimens beneath belong, and show the chemical com- 
position and system of crystallization of each species. The spec- 
imen labels show the name of the species, its number in Dana’s 
system, its museum number and the locality.* 
*Owing‘ to the ligThtingr of the hall from above, a good observation of 
the specimens is somewhat hindered by the reflection from the cases. In 
order to avoid this the observer is advised to view the specimens from the 
side rather than from the front. 
