26 



/. Instrument for the study of fatigue (Mosso) . 

 g. Instrument for accuracy of extent of movement (Cattell). 

 h. Instrument for right and lelt movements (Jastrow). 

 i. Instrument for time of movement ; w^ith chronoscope 

 (Cattell). 



GEOLOGY. 



In Charge of J. F. Kemp. 



Suite of Selected Specimens for Lecture-Room Use, 

 mostly dynamical in nature. 



Exhibited by Prof. R. E. Dodge, Teachers College. 



a. Slab of Cambridge Slate, to show faulting parallel to 

 the bedding. 



b. Obsidian from the Lipari Isles, showing conchoidal frac- 

 ture. 



c. Large sand-blasted pebble from Cape Cod, Mass. 



d. Slab of slate from Slate Island, Boston Harbor, to show 

 topographical effects of faults. 



e. Specimen of Roxbury conglomerate, showing particu- 

 larly large pebbles. 



f. Banded and faulted Dakota Sandstone. 



Suite of Specimens Showing the Contact Zone of the 

 Sierra Tlayacac, State of Morelos, Mexico, and illus- 

 trating a remarkable case of recrystallization of a sedi- 

 mentary rock by contact with eruptive masses. The 

 coarser and finer grained representatives of the darker 

 (earlier) eruptive and lighter (later) intrusion are shown. 

 The darker was shattei'ed by the disturbance attending 

 the eruption of the later rock. Exhibited by Prof. A. C. 

 Gill, Cornell University, Ithaca, N. Y. 



Mountain-building Studies. 



Numbers 3, 4, and 5 are exhibited by the Laboratory 



