616; ' CATALOGUE OF EXHIBITS. 



XI. Enlargements of Photographs of the Electric Arc, with 

 and without Metals. Exhibited by A. L. Foley ; 

 Cornell University. 



12. Enlargements of Photographic Traces made with the 



Hotchkiss Galvanometer. Exhibited by Prof. E. Mer- 

 RiTT ; Cornell University. 



13. Photographs of Traces of Gyroscopic Pendulum. Ex- 



hibited by Prof. E. Merrlit ; Cornell University. 



14. Thin Metallic Film High Resistances. Exhibited by A. 



C. LoNGDEN ; Columbia University. 



15. Newton's Rings in Thin Selenium Films. Exhibited by 



A. C. LoNGDEN ; Columbia University. 



16. Induction Apparatus, and X-ray Tube. Exhibited by E. 



L. Knott & Co.; Boston. 



17. Photograph of Manometric Flame Showing the Octave 



in the Forced Vibration of a Tuning Fork. Exhibited 

 by W. Hallock ; Columbia University. 



18. Modified Form of the Pupin Interrupter. Exhibited by 



W. Hallock ; Columbia University. 



19. Gelatine Half-wave-length Zone Plate. Exhibited by 



Prof R. W. Wood ; University of Wisconsin. 



PSYCHOLOGY. 



In Charge of Edw. L. Thorndike. 

 I. Preliminary Apparatus for Recording the Vibrations of 



the Human Voice. Exhibited by Professor C. H. Judd ; 



New York University School of Pedagogy. 

 2(a). Apparatus for Recording the Steadiness, Accuracy and 



rapidity of Very Small Movements, {b) Apparatus 



for Recording the Force of a Blow. Exhibited by Dr. 



R. S. Woodworth ; New York University Medical 



School. 



