1899.] SELLERS — TRANSMISSION OF ENERGY BY ELECTRICITY. 67 



The experiments of Mr. Tesla, which were directed toward the 

 utilization of an alternate electric current of high frequency, and 

 which were conducted in the interest of the Westinghouse Com- 

 pany, resulted in the issue of at least twenty-nine patents to cover 

 the multiphase generation of electricity. The first of these patents 

 was issued as early as 1888, and the last in 1891, and yet in 1893, 

 so far as I am aware, there were no examples of the Tesla motors 

 in commercial operation, for the reason that up to that time — and, 

 in fact, not until 1895 — the conditions had not been favorable to 

 its development. As soon as there seemed to be a demand for 

 their use, however, the manufacturers placed them on the market 

 with as high an efficiency as the best direct-current motors, with this 

 further advantage that is of the utmost importance : A direct- 

 current motor and a direct-current dynamo are limited in their 

 electro-motive force by the commutator necessary for their opera- 

 tion. The earliest alternating-current motors were what are known 

 as synchronous motors ; that is, motors that when started would run 

 in step with the dynamo from which the current proceeded. These 

 motors had no self-starting power, and involved many objectionable 

 features that are not incident to polyphase motors of the induction 

 type — in other words, what we know as the Tesla motor. In the 

 first place, and as of vital importance, a Tesla motor can be wound 

 to suit high voltage. Electricity at 2000 volts can be carried with 

 absolute safety by properly insulated cables into buildings and 

 applied directly to the motor without any live terminals ; that is, 

 without any part carrying current being exposed from which a dan- 

 gerous shock of electricity can be obtained. They are all self- 

 contained. They start with a powerful torque upon com- 

 pleting the circuit ; that is, they start when the switch is closed 

 and stop when the switch is open. Here is the possibility of an 

 ideal electric motor, which is perfectly well understood by profes- 

 sional electricians, but about which the public have yet to be more 

 thorouglily informed. 



Though I have said that little was known about the alternating 

 current in practice until lately, yet I have before me a copy of a 

 letter written by Mr. L. B. Stilhvell, one of our members, the Elec- 

 trical Director of the Niagara Falls Power Company, when he was on 

 the staff of the Westinghouse Company, dated May 11, 1893, in 

 which he said : "I received yesterday from our engineer in charge 

 of the installation at Pomona, Cal., a report of tests which he had 



