42 | ANNUAL REPORT OF THE 
REPORT ON THE GEOLOGICAL COLLECTION. 
By Rosert W. SAy Les. 
There have been added to the collections devoted to dynamical 
and structural geology, 194 specimens. Special mention may be 
made of 75 specimens of cave deposits, mainly stalactites and 
stalagmites from Bisbee, Arizona, and Hamilton Furnace, Missouri, 
purchased of the Mineralogical Department. This splendid ma- 
terial was collected by the late Dr. John B. Sweet of Boston. 
A case has been devoted to comparative tillites from. widely sepa- 
rated parts of the earth. This is the first exhibition in this country 
of its kind. Prof. W. W. Atwood has kindly given a striated 
pebble from the latest tillite reported, that found by him in the 
Lower Eocene of the San Juan Mountains, Arizona, in 1913. The 
sections of the cases in this room have been numbered to facilitate 
the finding of answers to the questions posted in the bulletin box. 
These questions and answers are for the aid of visitors in the 
understanding of the specimens and of geological processes. It 
is impossible for the visitor unless trained geologically to under- 
stand the meaning of all the exhibitions, without more expla- 
nation than is possible on the small specimen labels. This is 
especially true of geological specimens. 
The room devoted to economic geology has received 860 speci- 
mens. Of these about 500 were given by Prof. H. L. Smyth. 
The kindness of his gift is much appreciated. ‘These specimens 
are mainly examples of the metallic ores and minerals. The 
Mineralogical Department has also kindly given some specimens, 
mainly examples of the non-metallic ores and minerals. A col- 
lection of ornamental stones and marbles was purchased in Flor- 
ence, Italy. By the direction of the Curator, the specimens were 
mounted on heavy plate glass, in order that the coloring, structure, 
and properties of light transmission of each specimen might be 
seen to good advantage. This work, the first of its kind, was very 
successfully done by Giovanni Montelatici, Director of the Arte 
Musiva Fiorentina. The case devoted to building stones and 
road materials is being filled rapidly. Mr. G. M. Flint has given 
much skilful assistance in the preparation of the specimens illus- 
trative of economic geology. 
_ The Curator spent the summer of 1913 in visiting Italy, the 
Austrian Tyrol, and Switzerland. : 
