22 



Exhibited in this instance in connection -with the inves- 

 tigation of the action of "Magnetic circuit breakers" as 

 used in electric light and power circuits. 



6. Induction Coil with 20" Spark. Crookes tubes for use in 



making Rontgen ray photographs. Photographs of the 

 pelvis and thorax. An early arc lamp mechanism. Ex- 

 hibited by M. O'Connor. 



7. One Horse-Power Self-Starting Synchronous Motor. 



Starts by connecting one side of the armature and one 

 winding on the field as a series motor on an alternating 

 current circuit. When the proper speed has been at- 

 tained, a switch is thrown, thereby changing the alter- 

 nating current to the alternating current side of the arma- 

 ture and making the motor a synchronous one. The 

 former side of the armature now generates a direct elec- 

 tromotive force, which sends current through the field 

 windings, thus exciting them. 



8. Porcelain Insulator as used on the Niagara-Buffalo trans- 



mission line to support wires between which exists a 

 pressure of 10,000 volts. Nos. 7 ^"d S are exhibited 

 by the Electrical Engineering Department, Columbia 

 University. 



9. Induction Coil and Circuit Breaker for generation of 



Rontgen rays. Exhibited by M. I. Pupin. 



10. Special Crookes Tubes and Specimens of German Tubes 



for X-ray Work. Igniter for gas engines. Exhibited 

 by Max Osterberg. 



1 1 . Novel Arc Light Carbon Carrier. 



12. One of the two Original Henry Induction Coils. 



Nos. 1 1 and 1 2 are exhibited by R. Ogden Doremus. 



