74 o THE POPULAR SCIENCE MONTHLY. 



have set themselves the task of working out complete systems of 

 apparatus along the lines laid down by him. The Westinghouse 

 Company, which early secured control in this country of Mr. Tes- 

 la's inventions, has developed a system using a two-phase current^ 

 while the other considerable American company, the "General 

 Electric," has worked out a system employing a three-phase cur- 

 rent, which form of current has also been adopted by the Allge- 

 meine Elektricitats Gesellschaft of Berlin. All these companies 

 make an exhibit of this class of apparatus at the exposition, ar- 

 ranged to show the system in operation. The exhibits of the two 

 chief American companies are substantially the same, differing 

 mainly in the character of current used. Each shows the genera- 

 tion of multiphase currents, their transmission to the point of 

 distribution, and their utilization in alternating and direct current 

 apparatus. 



How completely the problem of the distribution of electrical 

 power over long distances has been solved by this system, and to 

 what extent we may expect to see it pass into commercial use, ex- 

 perience alone can determine. Disregarding its future utility, 

 when we will perforce be driven to the utilization of natural 

 powers, and looking only to the immediate present, it is not diffi- 

 cult to see that its adoption will be primarily determined by the 

 cost of operating local steam plants. Where fuel is abundant, 

 and hence cheap, there will be little inducement to resort to 

 sources of power at a distance, but in all situations in which this 

 condition does not obtain, and water power is to be had within a 

 reasonable distance, electric power transmission will find a field, 

 and one which will constantly widen with experience. While 

 the utilization of water powers is the most obvious use for electric 

 power transmissions, and certainly its most immediate one, it is 

 quite possible that it will not prove to be the only one. As is 

 well known, a large part of the cost of coal to the consumer is the 

 expense of hauling it from the mines. It has been often pointed 

 out that if the coal could be burned at the pit's mouth and its 

 energy transmitted to the place of use there might result a great 

 saving, but any economical method of doing this has heretofore 

 been wanting. The suggestion has many times been made to 

 convert the coal into gas and distribute this, but the cost of pip- 

 ing has heretofore rendered this method of eliminating the cost of 

 railroad carriage impracticable. It would seem, however, to be 

 quite within the range of practical possibilities to find in electric 

 transmission an efficient and economic method. 



[To be concluded,] 



