1899.] SELLERS — TRANSMISSION OF ENERGY BY ELECTRICITY. 65 



for each phase, while the tri-phase system is worked with three 

 cables only, each of the three cables being no larger than each of 

 the four demanded by the bi-phase system. This advantage had 

 been taken into consideration, but other economies incident to the 

 bi-phase had overbalanced the question of saving in copper in the 

 line. Before the line to Buffalo could be built, however, and as a 

 striking instance of an urgent need of exciting the talent of inventors 

 to supply the want, Mr. C. F. Scott, of the Westinghouse Company, 

 startled the electricians at a meeting in Washington with his scheme 

 of converting the bi-phase current into a tri-phase in the static 

 transformers that are used to raise the electro-motive force of the 

 current from 2200 volts to 11,000 volts or more — this without add- 

 ing one dollar to the actual cost of the transformers needed, and 

 with the saving of twenty-five per cent, in the copper used, which 

 must be credited to the tri-phase transmission. So that while the 

 low frequency adopted increased the efficiency of the plant, and 

 favored many operations of the power plant, the first cost was not 

 affected by the prophesied high cost of transformers, and all the ad- 

 vantages incident to both systems were obtained not only without 

 an increase of the first cost, but a direct saving in the copper of the 

 line. As the plant grew in size, many of the difficulties that had 

 been expected in handling such an immense volume of electricity 

 as was involved did not occur, and it was evident that the prac- 

 tical electricians attached to the great manufacturing establish- 

 ments of electrical machinery had brought the appliances needed 

 well up to the requirements of the new conditions. Every ma- 

 chine, every instrument needed, had to be contrived, not only to 

 suit the size of the unit of 5000 horse power, but to meet the 

 unknown effect of coupling so many great machines in parallel and 

 distributing the current to establishments over which the attendants 

 in the power-house have little or no control. 



In thus referring to the utilization of power at Niagara Falls, I 

 may seem to depart from the subject of transmission of energy, 

 although the development of the industries described is intended to 

 illustrate the direct results obtained by transmitted energy. The 

 energy developed at the dynamos in the power-house, and existing as 

 potential only while the dynamos are in motion, begins with an elec- 

 tro-magnetic force of 2200 volts, at which 5000 electrical horse power 

 is transmitted by four cables, each i^" in diameter, two cables 

 for each phase of each dynamo, to the bus bars from which the 



PROC. AMER. PHILOS. SOC. XXXYIII. 159. E. PRINTED JULY 17, 1899. 



